外文翻译-公路和机场路面设计

Newly built highway asphalt tong road surfaceearlytime damage analysisAbstract: Article damage which appears in view of the newly built highwayasphalt tong road surface early time, summarizes characteristic which it appears,analyzes reason which it forms, for seeks the preventing and controllingcountermeasure to provide the basis.Key word: Highway; Asphalt; tong road surface; Damage; AnalysisFirst, bituminous pavement conventional damage characteristic and origin (1)crack.The longitudinal crack is parallel basically to the path middle line, is apartfrom road edge 3~5m, sometimes follows has the few seams.The rectiunear figurecrack mainly is under the big load repetition function produces, assumes the arc also the both sides the crack which extends to the embankment edge mainly is formsbecause of the roadbed differential settlement.The transverse crack nearly is vertical to the path middle line, the spacing different, sometimes follows has the few seams, and increases year by year.Thebituminous pavement low temperature contraction and the semi-rigid basic unitcontraction crack response has the transverse crack two primary causes.At the same time, fills in digs the border the unequal settlement to be able to produce assumes the arc the transverse crack.The net crack initial shape is in appears the single scroll or the multi-strip parallel longitudinal seal along the wheelpath, after but appears crosswise or thediagonal company in during the parallel longitudinal seal joins, the cracking net, the partial concomitance settlement, squirts the thick liquid phenomenon, it is under the driving load repeatedly function, the partial structural-load-carrying capacityinsufficiency or the excessive subsidence produce.(2)distortion.The settlement refers to the asphalt tong road sign surface the part to behollow, it is, after or because partial excavates, the concomitance road surface knotconfiguration the backfill earth-pressure which the roadbed subsidence or thedifferential settlement distort create which solid insufficient creates destroys, after patching damages continues to develop.The wheel rut refers to bed which in the wheelpath appears, the external factor is the channelizing traffic and the load function number of times increases, the internal cause is asphalt concrete high temperature stable Holland anti-changes abilitydifference to have the lateral shear flow distortion.Pushes the distortion to refer in the vehicle speed frequent change street intersection and so on place, because the vehicles get on the brakes frequently and the start, road surface distortion which and under the great horizontal shear togetherfunction produces in the high temperature.(3) superficial damage.The weeping refers to in the bituminous pavement free asphaltbeing heated to inflate, because the asphalt concrete crevice is unable to hold, the asphalt migrates to the superficial phenomenon, the asphalt amount usedexcessively are many, the design percentage of voids excessively is small, thebituminous mixture segregation causes the smalls too to concentrate and theasphalt high temperature stability bad is upwardly causes the weeping theimportant reason.The weeping occurs in the weather burning hot season, but theweather cold season does not have the reversible process, affects the road surface structure depth and the anti-slippery performance.The polish is changes theaggregate pellet which the surface appears externally to be an expert to goodexpert the tire under the rubbing effect to change the smooth phenomenongradually.The primary cause is under the wheel repetition function, uses theaggregate not wear-resisting creates.Second, new damage phenomenon and origin(1)new weeping phenomenon.Oil stain weeping becomes which by the punctual oilstain development, occurs carries the SMA Holland to open the level to cultivate the asphalt concrete surface layer the road surface, separable three levels: Light, small oil stain diameter 1~2㎝fragmentary distribution; The oil stain increases increases, the diameter 1~5㎝different; Heavy, the oil stain diameter, the area or the densityincrease, gradually continually Large expanse of.The oil stain weeping has theuniversality, widely exists in SMA and in the AK anti-slippery surface layer roadsurface.。

土木工程英语证书（PEC）考试-道路勘测设计专业术语道路road公路highway都市道路city road；urban road厂矿道路factories and mines road林区道路forest road乡村道路country road车辆换算系数vehicle conversion factor城间道路interurban road都市出入口公路city approach highway道路工程road engineering丝绸之路the silk road道路网road metwork道路(网)密度density of road network道路技术原则technical standard of road设计车辆design vehicle特种车辆special vehicle计算行车速度(设计车速) design speed道路建筑限界boundary line of road construction道路用地范围right of way净空clearance等级道路classified road辅道relief road高速公路free way；motorway部分控制进入partial control of access等级公路classified highway等外公路substandard highway干线公路arterial highway支线公路feeder highway国家干线公路(国道) natilnal trunk highway省干线公路(省道) provincial trunk highway县公路(县道) county road乡公路(乡道) township road (county road)绕行公路bypass公路自然区划clinatic zoning for highway(都市)迅速路expressway(都市)主干路arterial road(都市)次干路secondary trunk road(都市)支路branch road街道street郊区道路suburban road居住区道路residential street工业区道路industial district road厂外道路ractory-out road厂内道路factory-in road(厂内)主干道arterial road(厂内)次干道secondary trunk road(厂内)支道branch road露天矿山道路opencast mine road生产干线prductive arterial road生产支线productive branch road联络线linking-up road林区公路fores thighway运材道路haul road集材道路skid road护林防火道路protection forest fire-proof road 连接道路linking-up road冻板道路freeze road木排道corduroy road自行车道cycle track；cycle path畜力车道cattle-pass驮道bridler road项目提议书project Proposal可行性研究feasibility study项目任务书Project charter设计规范design specification初步设计Preliminary Design施工图设计construction documents design 交通构成traffic composition混合交通mixed traffic交通流traffic flow车流vehicle stream交通密度traffic density车头间距spachead way车头时距time headway车(辆)间净距vehicular gap延误delay点速度spot speed行驶速度running speed区间速度overall speed运行速度operating speed临界速度iptimum speed；critical speed 时间平均速度time mean speed空间平均速度space mean speed经济车速economic speed自由车速free-flow speed交通量traffic volume年平均日交通量annual average daily traffic月平均日交通量monthly average daily traffic年第30位最大小时交通量thirtieth highest annual hourly volume 年最大小时交通量maximum annual hourly volume高峰小时交通量peak hourly volume设计小时交通量design hourly volume通行能力traffic capacity基本通行能力basic trsffic capacity也许通行能力possible traffic capacity设计通行能力design traffic capacity道路服务水平level of servic e交叉口通行能力capacity of imtersection道路交通规划traffic planning交通调查traffic survey交通量调查traffic volume survey交通量观测站traffic volume observation起迄点调查origin-destination study出行trip境内交通local traffic过境交通through traffic出境交通outbound traffic入境交通inboud traffic交通发生traffic generation交通分布traffic distribution交通方式划分model split交通量分派traffic assignment交通量预测traffic volume prognosis路网通行能力capacity of metwork道路网规划road network planning棋盘式道路系统gridiron road systim环形辐射式道路系统ring and radial road system自由式道路系统free style road system混合式道路系统combination-type road system(都市)道路面积率road area ratio(都市)人均道路面积road area ratio牵引力tractive effort行驶阻力driving resistance滚动阻力rolling resistance空气阻力air friction；air resistance坡度阻力slope resistance；grade resistance(都市道路)平面设计alignment design；plane design道路中线center line of road道路轴线road axis道路路线route of road道路线形road alignment平面线形horizontal alignment横向力系数lateral force ratio缓和曲线transition curve；easement curve离心加速度centrifugal acceleration回旋线spiral curve；clothoid交点intersection point, IP主点major point偏角angle of deflection偏角法method of deflection angle几何要素geometry element圆曲线参数parameter of circular curve切线支距法tangent offset method缓和曲线参数parameter of easement curve急弯sharp curve缓弯flat curve坐标coordinate线形要素alignment elment平曲线horizontal curve最小平曲线半径minimum radius of horizontal xurve 汽车最小转弯半径minimum turning radius圆曲线circular curve复曲线compound curve复曲线点point of compound curve, PCC反向曲线reverse curve同向曲线adjacent curve in one direction断背曲线broken-back curve回头曲线switch-back curve；reverse loop卵形曲线ovoid curve视线sight line视距sight distance停车视距stopping sight distance超车视距overtaking sight distance[司机]反应距离[driver]reaction distance[司机]感觉反应距离[driver] perception-reaction distance [司机]感觉反应时间[driver] perception-reaction time [司机]判断时间[driver] judgement time[司机]识别距离[driver] decipherment distance侧向视野field of lateral vision侧向余宽lateral clearance侧向最小安全间距minimum safe lateral clearance纵断面设计profile design；design of vertical alignment 纵面线形vertical alignment高程(标高) elevation地面高程groud elevation设计高程designed elevation(路线)纵断面图vertical profile map中桩填挖高度height of cut and fill at center stake纵坡longitudinal gradient最大纵坡maximum longitudinal gradient最小纵坡minimum longitudinal gradient变坡点grade change point平均纵坡average gradient坡长限制grade length limitation纵坡折减grade compensation缓和坡段transitional gradient竖曲线vertical curve凸形竖曲线convex vertical curve凹形竖曲线concave vertical curve路幅roadway车行道(行车道) carriage way车道lane内侧车道fast lane中间车道cemter lane外侧车道nearside lane附加车道auxiliary lane变速车道speed-change lane加速车道acceleration lane减速车道deceleration lane超车车道overtaking lane爬坡车道climbing lane停车车道parking lane紧急停车带emergency parking strip；lay-by错车道passing bay回车道(回车场) turmaround loop专用车道accommodation lane错车洞passing bay in tunnel单行路one-way road车道宽度lane-width人行道side walk；foot way分隔带separator；central reserve路缘带marginal strip路肩shoulder；verge硬路肩hard shoulder路缘石curb平缘石flush curb立缘石(侧石) vertical curb平石gutter apron街沟(偏沟) gutter路侧带curb side strip绿化带green belt横坡cross slope路拱crown路拱曲线camber curve合成坡度resultant gradient平曲线加宽curve widening加宽过渡段transition zone of curve widening超高superelevation超高缓和段superelevation runoff断面渐变段transition zone of cross section超高横坡度superelevation slope土方调配cut-fill transition土方调配图cut-fill transition program土方调配经济运距economical hauling distance横断面图cross-cectional profile路基subgrade路堤embankment路堑cutting半填半挖式路基part-cut part-fill subrade台口式路基benched subgrade路基宽度width of subgrade路基设计高程design elevation of subgrade(路基)最小填土高度minimum height of fill边坡side slope边坡平台plain stage of slope边坡坡度grade of side slope边坡修整slope trimming(边)坡顶top of slope(边)坡脚toe of slope护坡道berm边坡平台plain stage of slope碎落台stage for heaping soil and brocken rock 护坡slope protection挡土墙retaining wall重力式挡土墙gravity retaining wall衡重式挡土墙balance weight retaining wall悬臂式挡土墙cantilever retaining wall扶壁式挡土墙counterfort retaining wall柱板式挡土墙pile and plank retaining wall锚杆式挡土墙anchored retaining wall by tie rods 锚锭板式挡土墙anchored bulkhead retaining wall 加筋土挡土墙reinforced earth retaining wall石笼rock rilled gabion抛石riprap护栏guard rail护墙guard wall标柱guard post防护栅safety fence防炫屏(遮光栅) anti-dizzling screen隔音墙acoustic防沙设施sand protection facilities防雪设施snow protection facilities道路限界架boundary frame on road道路照明设施ighting facilies of road交通广场traffic square停车场parking lot反坡安全线adverse grade for safety公交(车辆)停靠站bus bay ；parking station综合管道(综合管廊) composite pipe line渡口ferry道路绿化road planting街道绿化street planting行道树street trees绿篱hedge；living fence功能栽植function planting护路林shelter belt里程碑ki lometer stone百米桩hectometer stake踏勘reconnaissance(道路工程)方案图road project(道路)平面示意图plane sketch线形设计alignment design公路景观设计highway landscape design(都市道路)竖向设计design of elevation选线route selection路线控制点control point定线location of line纸上定线paper location比较线alternative line展线route deveopment初测preliminary survey定测location survey地貌topographic feature地物culture地形topographyf台地terrace垭口pass；saddle back平原区plain terrain微丘区rolling terrain重丘区hilly terrain山岭区mountainous terrain沿溪线valley line山脊线ridge line山坡线(山腰线) hill-side line越岭线ridge line(道路)隧道tunnel半山洞half tunnel明洞open cut tunnel导线traverse导线测量traverse survey中线测量center line survey施工测量construction survey竣工测量final survey(路线)平面图plan view交点intersection point虚交点inaginary intersection point 转点turning point转角intersection angle偏角deflection angle方位角azimuth angle象限角bearing angle方向角direction angle切线长tangent length曲线长curve length外(矢)距external distance测站instrument station测点observation point中桩center stake加桩additional stake护桩reference stake断链broken chainage水准测量leveling survey水准点bench mark绝对基面absolute datum地形测量topographic survey基线base line地形图topographic map等高线comtour line横断面测量cross-sectional survey坑探intersection plan钻探boring(道路)地质剖面图geological section(道路)地质柱状图boring log地下水位uderground water level摄影测量photogrammetry航空摄影测量aerial photogrammetry地面立体摄影测量ground stereophotogrammetry地面控制点测量ground control-point survey航摄基线aerophoto base影像地图ohotographic map航摄像片判读aerophto interpretation综合法测图planimetric photo全能法测图universal photo微分法测图differential photo像片镶嵌图photo mosaic(平面)交叉口intersection；road crossing交叉口进口intersection entrance,approach交叉口出口intersection exit加宽转角式交叉口intersection with widende corners 拓宽路口式交叉口flaredintersection分道转弯式交叉口channelized intersection渠化交通channelization交错weaving交错路段weaving section合流converging分流diverging冲突点conflic t point交错点weaving point交通岛traffic island导流岛channelization island中心岛center-island安全岛refug island道口铺面paved crossing道口限界架boundary frame on crossing交通安全设施traffic safety device人行横道cross walk斑马线zebra crossing人行地道pedestrian underpass人行天桥pedestrian overcrossing分隔设施separate facilities视距三角形sight triangle路口视距sight distance of intersection标志视认性sign legibility(平曲线)横净距lateral elear distance of curvecut corner for sight line道路曲线最内侧旳车道行车(路口)截角视野field of vision道路交叉(路线交叉) Road intersection,crossing, junction 交叉角intersection angle(铁路)道口railroad grade crossing平面交叉at-grade intersection；grade crossing 多岔交叉multiple-leg intersection环形交叉rotary intersection；roundabout微形环交mini-roundabout十字形交叉cross roads丁字形交叉(T形交叉) T intersection错位交叉staggered junctionY形交叉Y intersection交叉口平面图intersection plan立体交叉grade-separated junction上跨铁路立体交叉overpass grade separation下穿铁路立体交叉underpass grade separation简朴立体交叉grade separation互通式立体交叉interchange苜蓿叶形立体交叉clover-leaf interchange半苜蓿叶形立交partial clover-leaf interchange定向式立体交叉directional interchange半定向式立交semi-directional interchange菱形立体交叉diamond in terchange喇叭形立体交叉trumpet interchange环形立体交叉rotary interchange分隔式立体交叉interchange woth special bicycle track 匝道ramp单向匝道one-wayramp双向匝道two-way ramp环形匝道loop ramp车道分布lane distribution车道分界线lane line车道平衡lane balance车道收费机lane toll machine车道通行能力lane capacity车道系数coefficient of lanes车道拥有率lane occupancy ratio出口匝道控制exit ramp control路基排水subgrade drainage地表水surface water地下水underground water毛细水capillary water边沟intercepting ditch截水沟intercepting ditch排水沟drainage ditch急流槽chute跌水drop water蒸发池evaporation pond盲沟blind drain；blind ditch渗水井seepage well过水路面ford暴雨强度intensity of rainstorm(排水)设计重现期design frequency街道排水street drainage管道排水pipe drainage渠道排水gutter drainage(立体交叉)泵站排水drainage by pumping station雨水口inlet；gully检查井manhole雨水口支管branch pipe of inlet泄水口drain opening取土坑borrow pit弃土堆waste bank管线综合设计under-ground pipes comprehensive design 路面pavement暗涵buried culvert饱和流量saturation volume饱和流率saturation volume rate暴雨径流rainstorm run-off暴雨强度rainstorm intensity。

英文翻译Flexible pavement designGenerally speaking,pavements(and bases) may be divided into two broad classifications or tipes:rigid and flexible. As commonly used in the United States,the term “rigid pavement”is applied to wearing surfaces constructed of Portland-cement concrete. A pavement constructed of concrete is assumed to possess considerable flexural strength that will permit it to act as a beam and allow it to bridge over minor irregularities which may occor in the base or subgrade on which it rests;hence the term “rigid”.Similarity,a concrete base that supports a brick or block layer might be described as “rigid”.All other types of pavement have traditionally been classed as “flexible”.A commonly used definition is that “a flexible pavement is a structure that maintains contact with and distributes loads to the subgrade and depends on aggregate interlock,particlefriction,and cohesion for stability”.Thus,the classical flexible pavement include primarily those pavement that are composed of a series of granular layers topped by a relatively thin high-quality bituminous wearing surface .Typically,the highest-quatily materials are at or near the surface.It should be pointed out that certain pavementsthat have an asphalt surface may behave more like the classical “rigid”pavement,for example, pavement that have very thick asphalt surface or that have base courses composed of aggregate treated with asphalt,cement, or lime-fly ash. However,for convenience of presentation,these pavements will be considered to be in the flexible class.The structure of flexible pavement is composed of a “wearing surface”, base, subbase(not always used), and subgrade . The wearing surface and the base often comprise two or more layers that are somewhat different in composition and that are put down in separate construction operations.On many heavy-duty pavements,asubbase of select material is often placed between the base and subgrade.the wearing surface may range in thickness from less than 1 in. in the case of a bituminous surface used for low-cost, light-traffic loads to 6 in. or more of alphaltconcrete used for heavily traveled routes. The wearing surface must be capable of withstanding the wear and abrasive effects of moving vehicles and must possess sufficient stability to prevent it from shoving and rutting under traffic loads. In addition,it serves a useful purpose in preventing the entrance of excessive quantities of surface water into the base subgrade from directly above.The base is a layer (or layers) of very high stability and density. Its principle purpose is to distribute or “spread” the stresses created by wheel loads acting on the wearing surface so that the stresses transmitted to the subgrade will not be sufficiently great to result in excessive deformation or displacement of that foundation layer. The base must also be of such character that it is not damaged by capillary water and/or frost action. Locally available materials are extensively used for base construction, and materials preferred for this type of construction vary wwidely in different sections of the country. For example, the base may be composed of gravel or crushed rock or it may bae a granular material treated with asphalt,cement,or lime-fly ash stabilizing agents.Asubbase of granular material or stabilized material may be used in areas where frost action is severe, in locations where the subgrade soil is extremely weak. It may also be used , in the interests of economy ,in locations where suitable subbase material are cheap than base materials of higher quality.The subgrade is the foundation layer, the structure that must eventually support all the loads which come onto the pavement. In some cases this layer will simply be the natural earth surface. In other or more usual instances it will be compacted soil existing in a cut section or the upper layer of an embankment section. In the fundamental concept of the action of flexible pavement,the combined thickness of subbase (if used), base, and wearing surface must be great enough to reduce the stresses occuring in the subgrade to values that are not sufficiently great to cause excessive distortion or displacement of the subgrade soil layer.The principle factors entering into the problem of the thickness design of flexible pavement are:(1)Traffic loading.(2)Climate or environment.(3)Material characteristics.A number of other elements must also be considered in order to arrive at a final thickness design. This include cost, construction, maintenance,an design period. Thus, the students should realize that the design process is complex, and it is highly unlikely that any extremely simple method of approach will prove entirely successful under all conditions.Protection of the subgrade from the loading imposed by traffic is one of the primariy functions of a pavement structure. The designer must privide a pavement that can withstand a large number of repeated applications of variable-magnitude loading.The magnitude of maximum loading is commonly controlled by legal load limits. Traffic surveys and loadometer studies are often used to establish the relative magnitude and occurrence of the various loading to which a pavement is subjected. Prediction or estimation of the total traffic that will use a pavement during its design ife is a very difficult but obviously important task.The climate or environment in which a flexible pavement is to be established has an important influence on the behavior and performance of the various in the pavement and subgrade. Probablly the two climate factors of major significance are temperature and moisture.The magnitude of temperature and its fluctuations affect the properties of certain materials. For example, high temperatures cause asphaltic concrete to lose stability whereas at low temperatures asphaltic concrete becomes very hard and stiff. Low temperature and temperature fluctuations are also associated with frost heave and freeze-thaw damage.Granular materials, if not properly graded, can experience frost heave. Likewise, the subgrade can exhibit extensive loss in strength if it becomes frozen. Certain stabilized materials (lime, cement, and lime-fly ash treated) can suffer substantial damage if a large number of freeze-thaw cycles occur in the material.Moisture also has an important influence on the behavior and performance ofmany materials. Moisture is an important ingredient in frost-related damage. Subgrade soils and other paving materials weaken appreciably when saturated, and certain clayey soil exhibit substantial moisture-included volume change.Subgrade moisture conditions change is affecting road structural strength, stiffness and stability of the important factors. Subgrade moisture influence has the following main factors: atmospheric precipitation and evaporation, infiltration of surface water, groundwater impact, temperature changes caused by humidity. Cyclical atmospheric temperature changes throughout the year, day and night temperatures for each day a certain extent cyclical changes. Surface directly exposed to the air, and experiencing the impact of these changes, in particular surface material most affected. Road surface temperature change with the weather temperature is roughly synchronized. Surface layer temperature at different depths within the same generation as the cyclical changes in atmospheric temperature, but the magnitude of change increases with the depth gradually decreased.One of frost damage is frozen, it not only affects the normal running of vehicles, and sometimes the destruction of the pavement structure. Produce frost heave for two reasons: First, as water is frozen, the volume will increase by 9%; second is due to the weak foundation soil to freeze the area with water movement results. Subgrade frost heaving caused by three factors: the sensitivity of frozen soil subgrade; temperature decreased slowly; groundwater supply of water to keep the frozen zone.The advent of spring, began to melt the frozen roadbed, will lose their bearing capacity of soil, leading to road damage, a phenomenon known as the spring melt boil, boil and mainly due to the melting process is top down, when the embankment top soil begins to melt, the water can not be excluded, so the soil has been saturated melting. If by this time a large number of heavy vehicles, road structure would be seriously damaged.Of the road is a sticky, elastic-plastic materials and the combination of mineral aggregate particles consisting of roads, including the addition of cement concrete as a surface layer and the surface structure of a variety of other grass-roots level. Flexible pavement design including pavement layer combination of design, structuralcalculation and the road pavement material mix design. This chapter elaborates the following aspects: elastic layered system theory, the pavement layer combination of design principles, road design standards and parameters, calculation of pavement thickness and the bending stress check.In reality, the road base material and the soil is not in any case have elastic properties. Non-linear elastic - viscous - plastic theory, under certain conditions more accurately describe the stress state of the road, but taking into account the role of the transient driving wheels in the pavement structure, the stress was small, so you can road as each layer is an ideal elastic body, multi-layer linear elastic theory to application to design calculations. Multi-layer linear elastic theory must be used the following basic assumptions:yers of material are continuous, homogeneous, isotropic and to obey Hooke's law, and the displacement and deformation is small;2. The next level (soil basis) in the horizontal direction and vertical direction down to infinity, The elastic layer is above all have a certain thickness, but the horizontal direction is infinite;3. layers of infinite distance in the horizontal direction and the next layer down to infinite depths, the stress, strain and displacement is zero;4. layers the contact conditions between fully continuous;5. do not count weight.Flexible Pavement Structure Design's mission is to design principles in general under the guidance of the road, according to the road level, requirements and design life of the cumulative equivalent standard axle load axle, considering the supply of road materials, the degree of influence of natural factors and the specific construction conditions, determine a reasonable level of the pavement structure and select the appropriate economic composition materials, combined into both withstand traffic loads and the role of natural factors, but also give full play to the maximum performance of structural materials, subgrade layer pavement system. Combination of flexible pavement structural design should follow the following basic principles:1, route, embankment, road do take into consideration the overall design;2, according to the structure, function and transport layer characteristics of selected structural levels;3, the strength to adapt to traffic load and stiffness combination;4, pay attention to its own characteristics each layer, make layer combination;5, the appropriate number of layers and thickness;6, to consider the impact of water temperature conditions to ensure stability.柔性路面设计一般来讲，路面（和路基）可以分为两种类型：刚性路面和柔性路面。

中英文对照外文翻译文献(文档含英文原文和中文翻译)英文原文：The Basics of a Good RoadWe have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads are still in service.If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:（1）Get water away from the road（2）Build on a firm foundation（3）Use the best materials（4）Compact all layers properly（5）Design for traffic loads and volumes（6）Design for maintenance（7）Pave only when ready（8）Build from the bottom up（9）Protect your investment（10）Keep good records1．Get water away from the roadWe can’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any layer of a road’sstructure can weaken that layer, leading to failure.In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moisture problems.To prevent these problems remember that water:• flows downhill• needs to flow someplace• is a problem if it is not flowingEffective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1⁄4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crown should be 1⁄2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drainthe road surface.Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.2．Build on a firm foundationA road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.3．Use the best materialsWith all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ballbearings, moving under loads.Angular particles are more stable than rounded particles.Asphalt and concrete pavement materials must be of the highest quality, designed for the conditions, obtained from established firms, and tested to ensure it meets specifications. 4．Compact all layersIn general, the more densely a material is compacted, the stronger it is. Compaction alsoshrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Goodcompaction of asphalt pavement lengthens its life.5．Design for traffic loads and volumesDesign for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road will carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for traffic loadings through a road’s life.6．Design for maintenanceWithout maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:• adequate ditches that can be cleaned regularly• culverts that are marked for easy locating in the spring• enough space for snow after it is plowed off the road• proper cross slopes for safety, maintenance and to avoid snow drifts• roadsi des that are planted or treated to prevent erosion• roadsides that can be mowed safelyA rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.Mark culverts with a post so they can be located easily.7．Pave only when readyIt is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.Don’t assume that laying down asphalt will fix a gravel road that is failing. Before you pave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.8．Ê Build from the bottom upThis commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.9．Ê Protect your investmentThe road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and iceDrainage —clean and repair ditches and culverts; remove all excess materialRoadside —cut brush, trim trees and roadside plantings, control erosionTraffic service —clean and repair or replace signsDesign roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.10．Keep good recordsYour maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.Good record keeping starts with an inventory of the system. It should include the history andsurface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions, shoulders, signs, and such structures as retaining walls and guardrails.Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.ResourcesThe Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presents the Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASER Manual (32 pp). These booklets contain extensive photos and descriptions of road surfacesto help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.Roadware, a computer program which stores and reports pavement condition information. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to provide five-year cost budgets and roadway repair/reconstruction priority lists.Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.Geotextiles in Road Construction/Maintenance andErosion Control, No. 16. Definitions and common applications of geotextiles on roadways and for erosion control.T.I.C. workshops are offered at locations around the state.Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpful articles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.译文：一个良好的公路的基础长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。

土木工程学院交通工程专业中英文翻译Road Design专业：交通工程英文原文The Basics of a Good RoadWe have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads are still in service.If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:（1）Get water away from the road（2）Build on a firm foundation（3）Use the best materials（4）Compact all layers properly（5）Design for traffic loads and volumes（6）Design for maintenance（7）Pave only when ready（8）Build from the bottom up（9）Protect your investment（10）Keep good records1．Get water away from the roadWe can’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any layer of a road’sstructure can weaken that la yer, leading to failure.In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moistureproblems.To prevent these problems remember that water:• flows downhill• needs to flow somepla ce• is a problem if it is not flowingEffective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1⁄4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crown should be 1⁄2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drainthe road surface.Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.2．Build on a firm foundationA road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.3．Use the best materialsWith all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ballbearings, moving under loads.Angular particles are more stable than rounded particles.Asphalt and concrete pavement materials must be of the highest quality, designed for the conditions, obtained from established firms, and tested to ensure it meets specifications.4．Compact all layersIn general, the more densely a material is compacted, the stronger it is. Compaction also shrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Goodcompaction of asphalt pavement lengthens its life.5．Design for traffic loads and volumesDesign for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road will carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for traffic loadings through a road’s life.6．Design for maintenanceWithout maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:• adequate ditches that can be cleaned regularly• culverts that are marked for easy locating in the spring• enough space for snow after it is plowed off the road• proper cross slopes for safet y, maintenance and to avoid snow drifts• roadsides that are planted or treated to prevent erosion• roadsides that can be mowed safelyA rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.Mark culverts with a post so they can be located easily.7．Pave only when readyIt is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.Don’t assume that laying down asphalt will fix a gravel road that is failing. Before you pave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.8．Ê Build from the bottom upThis commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.9．Ê Protect your investmentThe road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and iceDrainage —clean and repair ditches and culverts; remove all excess materialRoadside —cut brush, trim trees and roadside plantings, control erosionTraffic service —clean and repair or replace signsDesign roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.10．Keep good recordsYour maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.Good record keeping starts with an inventory of the system. It should include the history and surface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions, shoulders, signs, and such structures as retaining walls and guardrails.Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.ResourcesThe Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presents the Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASER Manual (32 pp). These booklets contain extensive photos and descriptions of road surfacesto help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.Roadware, a computer program which stores and reports pavement condition information. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to provide five-year cost budgets and roadway repair/reconstruction priority lists.Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.Geotextiles in Road Construction/Maintenance andErosion Control, No. 16. Definitions and common applications of geotextiles on roadways and for erosion control.T.I.C. workshops are offered at locations around the state.Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpful articles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.中文译文一个良好的公路的基础长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。

原文Highway Design and Construction: The Innovation Challenge Author: Robert E. Skinner Jr.Innovations and advances in research are changing the way highways are built in America.The Egyptians were pouring concrete in 2500 BC, and the Romans used it to construct the Pantheon and the Colosseum. By the mid-1800s, Europeans were building bridges with concrete, and the first “modern” concrete highway pavements appear ed in the latter part of the 19th century. Naturally occurring asphalts, which have been used for waterproofing for thousands of years, came into common use in road construction in the 1800s. The first iron bridge was constructed in 1774, but by the end of the 19th century steel had largely replaced iron in bridge construction. These materials—concrete, asphalt, and steel—are now the mainstays of highway and bridge construction throughout the world, as well as of most types of public works infrastructure. Concrete and steel, the most versatile of these materials, are used for bridges and other highway structures; concrete and asphalt are used for roadway pavements.Everyone is familiar with concrete, asphalt, and steel, and some of us have worked with them, perhaps on home improvement projects. This familiarity, coupled with the long history of their many uses, has led many otherwise technically savvy people to believe that these materials are well understood, that their performance can be easily and reliably predicted, and that the technical challenges in using them for highways were overcome long ago. However, such notions are largely incorrect and misleading.For example, consider concrete, which is a mixture of portland cement, sand, aggregate (gravel or crushed stone), and water. Its performance characteristics are determined by the proportions and characteristics of the components, as well as by how it is mixed and formed. The underlying chemical reactions of concrete are surprisingly complex, not completely understood, and vary with the type of stone. Steel may be added for tensile strength (reinforced concrete), and a variety of additives have been identified to improve the workabilityand performance of concrete in particular applications and conditions. Damage and deterioration to concrete can result from excessive loadings and environmental conditions, such as freeze-thaw cycles and chemical reactions with salts used for deicing._________________________Many factors contribute to theurgent need for innovation inhighway construction._________________________Concrete is the most heavily used substance in the world after water (Sedgwick, 1991). Worldwide, concrete construction annually consumes about 1.6 billion tons of cement, 10 billion tons of sand and crushed stone, and 1 billion tons of water (M.S. Kahn, 2007). Given transportation costs, there is a huge financial incentive to using local sources of stone, even if the properties of that stone are less than ideal. Thus concrete is not a homogenous material. In truth, an unlimited number of combinations and permutations are possible.Much the same can be said of asphalt—technically, asphaltic concrete—which is also a mixture of aggregate (gravel or crushed stone), sand, and cement (asphalt binder); economics promote the use of locally available materials; and the underlying chemistry is not well understood. The characteristics of asphalt binder, for instance, vary depending on the source of crude oil from which it is derived.The metallurgy of steel is probably better understood than the chemistry of either asphalt or concrete, but it too is a mixture with virtually limitless combinations. Strength, toughness, corrosion resistance, and weldability are some of the performance characteristics that vary with the type of steel alloy used and the intended applications.As uses evolve and economic conditions change, we have a continuing need for a more sophisticated understanding of these common materials. Even though they are “mature” products, there is still room for significant incremental improvements in their performance. Because fundamental knowledge is still wanting, there is also considerable potential for breakthroughs in their performance.Factors That Affect Highway ConstructionAll other things being equal, stronger, longer lasting, less costly highway materials are desirable and, given the quantities involved, there are plenty of incentives for innovation. In highway transportation, however, all other things are not equal. A number of other factors contribute to the urgent and continuing need for innovation.First, traffic volume and loadings continue to increase. Every day the U.S. highway network carries more traffic, including heavy trucks that were unimagined when the system wasoriginally conceived and constructed. The 47,000-mile interstate highway system today carries more traffic than the entire U.S. highway system carried in 1956 when the interstates were laid out. The U.S. Department of Transportation (DOT) estimates that in metropolitan areas the annual cost of traffic congestion for businesses and citizens is nearly $170 billion (PB Consult, Inc., 2007).On rural interstates, overall traffic more than doubled between 1970 and 2005; at the same time, the loadings on those highways increased six-fold, mainly due to the increase in the number of trucks and the number of miles they travel. (Truck traffic increased from about 5.7 percent of all vehicle-miles traveled on U.S. highways in 1965 to 7.5 percent in 2000 [FHWA, 2005]).Second, traffic disruptions must be kept to a minimum during construction. Our overstressed highway system is not very resilient. Thus disruptions of any sort, such as lane and roadway closings, especially in major metropolitan areas and on key Interstate routes, can cause massive traffic snarls. This means that repair and reconstruction operations must often be done at night, which introduces a variety of additional complexities and safety issues. Occasionally, heroic measures must be taken to keep traffic moving during construction. For example, during construction of the “Big Dig” in Boston, the elevated Central Artery was in continuous service while cut-cover tunnels were constructed directly below it.Third, environmental, community, and safety requirements have become more stringent. For many good reasons, expectations of what a highway should be, how it should operate, and how it should interact with the environment and adjacent communities are constantly evolving. Designs to promote safety, measures to mitigate a growing list of environmental impacts, and attention to aesthetics have fundamentally changed the scope of major highway projects in the United States. For example, on Maryland’s $2.4 billion Intercounty Connector project in suburban Washington, D.C., which is now under construction, environmental mitigation accounts for 15 percent of project costs, or about $15 million per mile (AASHTO, 2008). Fourth, costs continue to rise. Building and maintaining highways cost effectively is an ever-present goal of good engineering. But cost increases in highway construction have been extraordinary due in part to the expanded scope of highway projects and construction in demanding settings. In addition, the costs of the mainstay materials—portland cement, asphalt binder, and steel—have risen dramatically as the world, particularly China, has gone on a construction binge. The Federal Highway Administration’s cost indices for portland cement concrete pavement, asphalt pavement, and structural steel increased by 51 percent, 58 percent, and 70 percent respectively between 1995 and 2005 (FHWA, 2006).Fortunately, research and innovation in construction have never stopped, although they are not always sufficiently funded and they seem to fly beneath the radar of many scientists and engineers. Nevertheless, there have been great successes, which are cumulatively changing how highways are built in America.The Superpave Design SystemIn response to widespread concerns about premature failures of hot-mix asphalt pavements in the early 1980s, a well funded, congressionally mandated, crash research program was conducted to improve our understanding of asphalt pavements and their performance. The seven-year Strategic Highway Research Program (SHRP), which was managed by the National Research Council, developed a new system of standard specifications, test methods, andengineering practices for the selection of materials and the mix proportions for hot-mix asphalt pavement.The new system has improved matches between combinations of asphalt binder and crushed stone and the climatic and traffic conditions on specific highways. State departments of transportation (DOTs) spend more than $10 billion annually on these pavements, so even modest improvements in pavement durability and useful life can lead to substantial cost savings for agencies and time savings for motorists (TRB, 2001).SHRP rolled out the Superpave system in 1993, but it took years for individual states and their paving contractors to switch to the new system, which represents a significant departure, not only in design, but also in the procedures and equipment used for testing. Each state DOT had to be convinced that the benefits would outweigh the modest additional costs of Superpave mixes, as well as the time and effort to train its staff and acquire necessary equipment.A survey in 2005 showed that 50 state DOTs (including the District of Columbia and Puerto Rico) were using Superpave (Figure 1). The remaining two states indicated that they would be doing so by the end of 2006. Throughout the implementation period, researchers continued to refine the system (e.g., using recycled asphalt pavements in the mix design [TRB, 2005]).It may be years before the cost benefits of Superpave can be quantified. A 1997 study by the Te xas Transportation Institute projected that, when fully implemented, Superpave’s annualized net savings over 20 years would approach $1.8 billion annually—approximately $500 million in direct savings to the public and $1.3 billion to highway users (Little et al., 1997).Moreover, analyses by individual states and cities have found that Superpave has dramatically improved performance with little or no increase in cost. Superpave is not only an example of a successful research program. It also demonstrates that a vigorous, sustained technology-transfer effort is often required for innovation in a decentralized sector, such as highway transportation.Prefabricated ComponentsThe offsite manufacturing of steel and other components of reinforced concrete for bridges and tunnels is nothing new. But the need for reconstructing or replacing heavily used highway facilities has increased the use of prefabricated components in startling ways. In some cases components are manufactured thousands of miles from the job site; in others, they are manufactured immediately adjacent to the site. Either way, we are rethinking how design and construction can be integrated.When the Texas Department of Transportation needed to replace 113 bridge spans on an elevated interstate highway in Houston, it found that the existing columns were reusable, but the bent caps (the horizontal connections between columns) had to be replaced. As an alternative to the conventional, time-consuming, cast-in-place approach, researchers at the University of Texas devised new methods of installing precast concrete bents. In this project, the precast bents cut construction time from 18 months to slightly more than 3 months (TRB, 2001).As part of a massive project to replace the San Francisco-Oakland Bay Bridge, the California Department of Transportation and the Bay Area Toll Authority had to replace a 350-foot, 10-lane section of a viaduct on Yerba Buena Island. In this case, the contractor, C.C. Myers, prefabricated the section immediately adjacent to the existing viaduct. The entire bridge was then shut down for the 2007 Labor Day weekend, while the existing viaduct was demolished and the new 6,500-ton segment was “rolled” into place (Figure 2). The entire operation was accomplished 11 hours ahead of schedule (B. Kahn, 2007).Probably the most extensive and stunning collection of prefabricated applications on a single project was on the Central Artery/Tunnel Project (“Big Dig”) in Boston. For the Ted Williams Tunnel, a dozen 325-foot-long steel tunnel sections were constructed in Baltimore, shipped to Boston, floated into place, and then submerged. However, for the section of the tunnel that runs beneath the Four Points Channel, which is part of the I-90 extension, bridge restrictions made this approach infeasible. Instead, a huge casting basin was constructed adjacent to the channel where 30- to 50-ton concrete tunnel sections were manufactured The basin was flooded and the sections winched into position with cables and then submerged.An even more complicated process was used to build the extension tunnel under existing railroad tracks, which had poor underlying soil conditions. Concrete and steel boxes were built at one end of the tunnel, then gradually pushed into place through soil that had been frozen using a network of brine-filled pipes (Vanderwarker, 2001).Specialty Portland Cement ConcretesNew generations of specialty concretes have improved one or more aspects of performance and allow for greater flexibility in highway design and construction. High-performance concrete typically has compressive strengths of at least 10,000 psi. Today, ultra-high-performance concretes with formulations that include silica fume, quartz flour, water reducers, and steel or organic fibers have even greater durability and compressive strengths up to 30,000 psi. These new concretes can enable construction with thinner sections and longer spans (M.S. Kahn, 2007).Latex-modified concrete overlays have been used for many years to extend the life of existing, deteriorating concrete bridge decks by the Virginia DOT, which pioneered the use of very early strength latex-modified concretes for this application. In high-traffic situations, the added costs of the concrete have been more than offset by savings in traffic-control costs and fewer delays for drivers (Sprinkel, 2006).When the air temperature dips below 40， costly insulation techniques must be used when pouring concrete for highway projects. By using commercially available admixtures that depress the freezing point of water, the U.S. Cold-Weather Research and Engineering Laboratory has developed new concrete formulations that retain their strength and durability at temperatures as low as 23?F. Compared to insulation techniques, this innovation has significantly decreased construction costs and extended the construction season in cold weather regions (Korhonen, 2004).As useful as these and other specialty concretes are, nanotechnology and nanoengineering techniques, which are still in their infancy, have the potential to make even more dramatic improvements in theperformance and cost of concrete.Waste and Recycled MaterialsHighway construction has a long history of using industrial waste and by-product materials. The motivations of the construction industry were simple—to help dispose of materials that are otherwise difficult to manage and to reduce the initial costs of highway construction. The challenge has been to use these materials in ways that do not compromise critical performance properties and that do not introduce substances that are potenti-ally harmful to people or the environment. At the same time, as concerns about sustainability have become more prominent in public thinking, the incentives to use by-product materials have increased. In addition, because the reconstruction and resurfacing of highways create their own waste, recycling these construction materials makes economic and environmental sense.Research and demonstration projects have generated many successful uses of by-product and recycled materials in ways that simultaneously meet performance, environmental, and economic objectives. For example, “crumb rubber” from old tires is increasingly being used as an additive in certain hot-mix asphalt pavement designs, and a number of patents have been issued related to the production and design of crumb rubber or asphalt rubber pavements (CDOT, 2003; Epps, 1994).Several states, notably California and Arizona, use asphalt rubber hot mix as an overlay for distressed flexible and rigid pavements and as a means of reducing highway noise. Materials derived from discarded tires have also been successfully used as lightweight fill for highway embankments and backfill for retaining walls, as well as for asphalt-based sealers and membranes (Epps, 1994; TRB, 2001).Fly ash, a residue from coal-burning power plants, and silica fume, a residue from metal-producing furnaces, are increasingly being used as additives to portland cement concrete. Fly-ash concretes can reduce alkali-silica reactions that lead to the premature deterioration of concrete (Lane, 2001), and silica fume is a component of the ultra-high-performance concrete described above.After many years of experimentation and trials, reclaimed asphalt pavement (RAP) is now routinely used in virtually all 50 states as a substitute for aggregate and a portion of the asphalt binder in hot-mix asphalt, including Superpave mixes. The reclaimed material typically constitutes 25 to 50 percent of the “new” mix (TFHRC, 1998). The National Asphalt Pavement Association estimates that 90 percent of the asphalt pavement removed each year is recycled and that approximately 125 millions tons of RAP are produced, with an annual savings of $300 million (North Central Superpave Center, 2004).Visualization, Global Positioning Systems, and Other New Tools For more than 20 years, highway engineers have used two-dimensional, computer-aided drafting and design (CADD) systems to accelerate the design process and reduce costs. The benefits of CADD systems have derived essentially from automating the conventional design process, with engineers doing more or less what they had done before, although much faster and with greater flexibility.New generations of three- and four-dimensional systems are introducing new ways of designing roads, as well as building them (Figure 4). For example, three-dimensional visualization techniques are clearly useful for engineers. But, perhaps more importantly, they have improved the communication of potential designs to affected communities and public officials; in fact, they represent an entirely new design paradigm. Four-dimensional systems help engineers and contractors analyze the constructability of proposed designs well in advance of actual constructionGlobal positioning systems are being used in surveying/layout, in automated guidance systems for earth-moving equipment, and for monitoring quantities. Other innovations include in situ temperature sensors coupled with data storage, transmission, and processing devices that provide onsite information about the maturity and strength of concrete as it cures (Hannon, 2007; Hixson, 2006).ConclusionThe examples described above suggest the wide range of exciting innovations in the design and construction of highways. These innovations address materials, roadway and bridge designs, design and construction methods, road safety, and a variety of environmental, community, and aesthetic concerns. Looking to the future, however, challenges to the U.S. highway system will be even more daunting—accommodating more traffic and higher loadings; reducing traffic disruptions during construction; meeting more stringent environmental, community, and safety requirements; and continuing pressure to reduce costs. Addressing these challenges will require a commitment to innovation and the research that supports innovation.中文翻译高速公路设计与施工：创新的挑战作者：小罗伯特·E·斯金纳研究方式的创新和进步正在改变着美国公路建设的方式。

中英文对照外文翻译文献(文档含英文原文和中文翻译)译文：交通系统交通运输一直是土木工程最重要的一个方面。

古罗马工程师的巨大成就之一就是公路系统，它使罗马与帝国的各个省之间的快速交通成为可能。

在工程方面的第一所培训学校就是桥梁和公路学校，它于1747年创建于法国。

而在英国，一位道路建筑家，托马斯·泰尔福特于1820年担任了土木工程学会的第一任主席。

现代公路仍然根据18世纪及19世纪初法国人皮埃尔·特埃萨凯，英国人泰尔福特，以及苏格兰人约翰·L·马克当所制定的原则进行建造。

这些人设计出了最初的现代道路，这种道路具有坚实的垫层，基础就建在垫层的上面。

他们设计的道路还具有排水良好而且不渗水的磨耗层，即直接承受车辆交通磨耗的表层。

特埃萨凯和泰尔福特均采用较厚的石头基础，在其上面铺筑由较小碎石组成的基层和由更小的石头组成的磨耗层。

他们的道路还微微隆起成曲线，形成路拱和反拱以便使雨水流走。

马克当认识到当土壤被夯实或压紧之后，只要保证干燥，其本身就可承受道路的重量，因而他能够通过在压实的垫层上铺碎石基层来省掉建造石头基础所需要的昂贵费用。

当时车辆的铁质车轮把表层石头碾压成连续的，较为平整的，更加不透水的表面。

早19世纪，货车和客车都采用铁或钢制车轮，这种道路是适用的。

当汽车在20世纪初出现之后，其橡胶轮胎毁坏了这种平整的路面。

因此，就采用焦油或沥青掺拌碎石，使路面表层更坚固的黏合一起。

现在，遍布全世界的数百万公里的道路采用这种路面。

在20世纪，道路建设基本上仅在两方面进行了改进。

第一种改进是采用混凝土作为磨耗层。

另一种改进则是交通工程，即设计高速的大交通量的、造价经济并且对于车辆和旅客都安全的公路。

交通工程已建成了现代高速公路，这种公路具有限定的入口和最安全的管理。

老式道路常用的拐角形交叉已不使用，而采用互通式立体交叉或其他更为复杂的设计。

现代高速公路通常设有专门的车道，在那里当车辆要驶出公路时可减速驶入时可加速。

附录A 外文翻译A.1 原文CONSISTENCY IN DESIGN FOR LOW-VOLUMERURAL ROADS3By Clarkson H. Oglesby, H. M. ASCE (Reviewed by the Highway Division) ABSTRACT: The 2,000,000 miles of low-volume rural roads in the United States are different than the high-volume roads and should be designed differently. Traffic volumes on them are low, averaging about 110 vehicles/day or about one vehicle entering a given mile from both ends every three minutes during peak hours. This contrasts with one vehicle every four seconds at capacity. Geometries on many of these roads have not changed since they were built in the 1920s and 1930s. Today, road improvements should be based on designs that are consistent and safe, but economical, because needs are great and funds are scarce. Present-day design practices for high volume roads require that each of their features meet a stipulated design speed set by modern surfaces and vehicles. This practice does not fit the low-volume situation since, whenever possible, drivers will exceed any affordable design speed. They must be slowed down when situations warrant it. A consistent approach to design which realizes cheap but safe improvements to low-volume roads is proposed. It involves integrating geometric design and positive guidance approaches. Positive guidance employs striping, signing, and other devices and strategies to mobilize drivers' senses so that they will drive sensibly. Selecting the less costly between geometry and positive guidance techniques will produce safer roads more cheaply.INTRODUCTIONThere are approximately 3,200,000 mile (5,100,000 km) of rural roads in the United States. A rough estimate places some 2,000,000 (3,000,000km) of these in a low-volume category; this commonly includes those with average daily traffic less than 400 vehicles/day in both directions. On most of these roads volumes are considerably lower. One estimate places this average at 110 vehicles/day or a possible 20 in the peak hour. This means one vehicle every three minutes entering a given mile from both ends. In contrast, a major two-lane road, operating at capacity, will carry possibly 1,800 vehicles/hour so that a vehicle will enter a given mile every four seconds or 90 times as often.The money available to those responsible for high-volume roads is on the order of ten times as great per mile as for low-volume roads. It follows that strategies for new construction, upgrading, or maintenance of low-volume rural roads will be entirely different than for higher-volume roads, if the very limited money availablefor these purposes is to be used wisely.Given the uniqueness of the low-volume road problem, it seems appropriate to examine and possibly redefine what is meant by "consistency in design" for them. This paper attempts that task by examining the following topics as it applies to them:1. The origin and current status of local rural roads.2. How "consistency" in present-day geometric standards for new construction or renovation of low-volume roads has developed.3. Factors that have impinged on design standards for low-volume rural roads.4. Conclusions.ORIGIN AND CURRENT STATUS OF LOCAL RURAL ROADS For the purpose of this paper, local rural roads are those that provide access to and thereby support activities on rural lands. These include farming, ranching, recreation, and access to forests or other natural resources. This definition excludes those roads, once rural or near towns, that are now in suburbia.Relatively little mileage has been added to low-volume rural systems in the last 50 years. They were developed when the aim was "to get the farmer out of the mud." They are often characterized by narrow roadways and rights-of-way. In the middle west and west, where much of the land had been laid out in sections one mile square, rights-of-way were 66 ft (20 m). This width was dedicated to land access along the edges of adjacent sections. In the eastern states, many rights-of-way were narrower, often 33 ft (10 m) or less. In rolling or mountainous country, tortuous alignments were fitted closely to the contour of the ground. Today these often restrict speeds to 30 mile/hr (48 km/h) or less.In these earlier years, travel was mainly in horse-drawn vehicle. Even in the 1930s, when the last of these land-access roads were being constructed, speeds were low because neither vehicles nor road surfacings permitted fast travel. For reasons such as these, the concept of design speed did not exist. Today, the performance of motor vehicles is far different and the sizes and weights of trucks have increased dramatically. Furthermore, for possibly two-thirds of this low-volume rural mileage, gravel or earth surfaces have been paved, surface treated, or otherwise made relatively smooth and free of corrugations or dust. Presently, then, drivers expect to travel at higher speeds and only slow down when forced to do so by intersections or restricted vertical or horizontal alignment. On higher volume roads, many of which have been successively improved, this slowing is seldom required. And when it is, elaborate measures are taken to alert drivers. But this matching of improvements with speed has been far less frequent on low-volume rural roads because money has been scarce. Of that available, more than two-thirds (in 1978) has gone to maintenance and other purposes, leaving little for new construction or betterment.It would be untrue and unfair to say that those responsible for low-volume rural roads have done nothing to overcome this mismatch between driver expectations regarding speed and the roads. Through strategies such as spot improvements and scrounging money from their budgets and higher governmental levels for rebuilding certain roads, they have done much. But the gap still remains large. This, of course, applies not only to road geometry, but to surfacings and bridges as well.How CONSISTENCY IN PRESENT-DAY GEOMETRIC STANDARDS FOR NEWCONSTRUCTION OR RENOVATION OF LOW VOLUME RURAL ROADS HAS DEVELOPEDAs noted, most of the need for and geometries of low-volume rural roads developed fifty or more years ago to fit specific situations. Unless altered by maintenance, betterment, reconstruction, or complete replacement, they have changed little since. At that time, main rural roads were built to meet the same conditions and their geometry was not an issue. For example, as late as 1940, a leading highway engineering text book, by T. R. Agg (1), devotes only 22 pages to the entire subject of geometric design. In it Agg stated that "considerable latitude is allowable in adapting the design to the particular situation (which may be topographical, financial, or political) as long as the design does no violence to basic principles." Agg calls for "the exercise of originality and good engineering judgment—that does not necessarily follow stereotyped standards."It was at about this same time (1937) that AASHO (now AASHTO) created a Committee on Planning and Design Policies. Its aim was to incorporate, in practice, highway design features that would result in maximum safety and utility. From this effort, in the period 1938-1944, came seven policy statements on geometric design that were adopted by AASHO. These were consolidated without change in 1950 into a single volume, Policies on Geometric Highway Design (3). A reworking resulted in a 1954 document called A Policy on Geometric Design (4). This document, commonly called the Blue Book, was redone again and published in 1965 under the same title (5). In 1969, a publication applying more specifically to low-volume rural roads was issued (2). Since that time the appropriateness of these policies, which set standards for all aspects of geometric design, have been under almost continuous review and a comprehensive revision is under preparation.From the beginning, those responsible for developing standards for geometric design have been attempting to keep pace with changes in the characteristics of motor vehicles and the expectations of drivers. This has led to a substantial raising of design controls or features.FACTORS THAT HAVE IMPINGED ON GEOMETRIC STANDARDSFOR LOW-VOLUME RURAL ROADSIn tracing the development of geometric standards and their application over the years in terms of their impact on low-volume rural roads policies, several factors can be seen. These include the following:1. Low-volume road engineers or administrators have made few direct inputs into geometric standards. They have been developed by specialists in geometric design, most of them in the Federal Highway Administration. They were adopted after review by geometric-design specialists in the state highway agencies working through AASHTO. Because these agencies deal primarily with high-volume situations, it is claimed that their representatives are not sensitive to the low-volume road situation. For example, the standards for low-volume as well as those for high-volume roads were based on the "design speed" concept, which has been defined as "The maximumsafe speed that can be maintained over a specific section of highway when conditions are so favorable that the design features of the highway govern." This definition implies that only the "reckless few" among drivers will exceed the design speed anywhere along the road. But this is not the way drivers behave on low-volume rural roads. Rather, whenever possible, even on short stretches, they will accelerate to their "fear level" speed. This can well be 50 or 60 mph (80 or 96 km/h) on a road with a stipulated. design speed of 20 or 30 mph (32 or 48 km/h). The problem on such roads becomes one of slowing drivers down to safe speeds as they approach road sections over which they must travel slowly. It might be said that the low "design speeds" stipulated in the standards for certain low-volume roads provide justification and professional support for designers using less costly alternatives at specific locations so that scarce dollars can be spread over greater mileages. Otherwise the "design speed" concept has little meaning in the low-volume rural road situation.2. Standards, once adopted, can become a straitjacket that prevents low-volume road engineers from following Agg's recommendation from 1940 which, to repeat, was "to allow considerable latitude in adapting the design to particular situations (topographical, financial, or political)." This freedom began to disappear when higher-level agencies, because they controlled the money, could dictate design details. Low-volume road engineers sometimes partially overcame this difficulty by having two sets of standards. The more costly set is employed when money from higher-level agencies is involved. The less costly one, done with local funds, does not have a standard cross section, but calls for widening or other improvements at spot locations.A related issue is the influence of these rigid standards when injured motorists sue road agencies and their engineers for negligence when roads do not meet them. This is an important but unanswered question.3. There has been a widely held but unproved notion that by insisting that standards of geometric design be followed, accidents will be reduced. Unfortunately, given the large mileage on existing low-volume roads and scarce funds for improving their geometry, exercising this option is seldom possible. Rather, for low-volume roads, the view that "The design is inadequate and appears dangerous so accidents happen" must be replaced with the notion, "if it seems dangerous, take advantage of driver fear and caution in appropriate ways and accidents won't happen." CONCLUSIONThis paper, which deals with consistency in design standards for lowvolume rural roads, has traced the development for low-volume rural roads, most of which came into being when the aim was to get the farmer out of the mud. It indicated how high geometric design standards, which came later, were developed by those concerned with high volume roads, but who dictated their use because they controlled the money. It challenged the notion that "if it seems dangerous, accidents happen," and proposed that "if it seems dangerous, accidents don't happen." It pointed out that vehicle, road, and driver all combine in safe and efficient vehicle operation; and that as the level of improvement dropped, the driver's ability became more and more important. It described the concept of "positive guidance" and proposed that, at least for low-volume rural roads, consistency in design be redefined to include bothgeometry and positive guidance. Given measures of the relative costs and potential for accident reduction of geometry and guidance, choices could be made rationally.A.2 译文低流量农村公路的统一设计由Clarkson·奥格尔斯比，H. M. ASCE(公路司)摘要：美国的200万英里的低流量的农村公路与高流量的道路不同，应采用不同的设计。

英文原文The Basics of a Good RoadWe have known how to build good roads for a long time. Archaeologists have found ancient Egyptian roadsthat carried blocks to the pyramids in 4600 BCE. Later,the Romans built an extensive road system, using the same principles we use today. Some of these roads are still in service.If you follow the basic concepts of road building, you will create a road that will last. The ten commandments of a good road are:（1）Get water away from the road（2）Build on a firm foundation（3）Use the best materials（4）Compact all layers properly（5）Design for traffic loads and volumes（6）Design for maintenance（7）Pave only when ready（8）Build from the bottom up（9）Protect your investment（10）Keep good records1．Get water away from the roadWe ca n’t overemphasize the importance of good drainage.Engineers estimate that at least 90% of a road’s problems can be related to excess water or to poor waterdrainage. Too much water in any layer of a road’sstructure can weaken that layer, leading to failure.In the surface layer, water can cause cracks and potholes. In lower layers it undermines support, causing cracks and potholes. A common sign of water in an asphalt road surface is alligator cracking — an interconnected pattern of cracks forming small irregular shaped pieces that look like alligator skin. Edge cracking, frost heaves, and spring breakup of pavements also point to moisture problems.To prevent these problems remember that water:• flows downhill• needs to flow someplace• is a problem if it is not flowingEffective drainage systems divert, drain and dispose of water. To do this they use interceptor ditches and slopes,road crowns, and ditch and culvert systems.Divert —Interceptor ditches, located between the road and higher ground along the road, keep the water from reaching the roadway. These ditches must slope so they carry water away from the road.Drain —Creating a crown in the road so it is higher along the centerline than at the edges encourages water to flow off the road. Typically a paved crown should be 1⁄4" higher than the shoulder for each foot of width from the centerline to the edge. For gravel surfaces the crown should be 1⁄2" higher per foot of width. For this flow path to work, the road surface must be relatively water tight. Road shoulders also must be sloped away from the road to continue carrying the flow away. Superelevations (banking) at the outside of curves will also help drainthe road surface.Dispose —A ditch and culvert system carries water away from the road structure. Ditches should be at least one foot lower than the bottom of the gravel road layer that drains the roadway. They must be kept clean and must be sloped to move water into natural drainage. If water stays in the ditches it can seep back into the road structure and undermine its strength. Ditches should also be protected from erosion by planting grass, or installing rock and other erosion control measures. Erosion can damage shoulders and ditches, clog culverts, undermine roadbeds, and contaminate nearby streams and lakes. Evaluate your ditch and culvert system twice a year to ensure that it works. In the fall, clean out leaves and branches that can block flow. In spring, check for and remove silts from plowing and any dead plant material left from the fall.2．Build on a firm foundationA road is only as good as its foundation. A highway wears out from the top down but falls apart from the bottom. The road base must carry the entire structure and the traffic that uses it.To make a firm foundation you may need to stabilize the roadbed with chemical stabilizers, large stone called breaker run, or geotextile fabric. When you run into conditions where you suspect that the native soil is unstable, work with an engineer to investigate the situation and design an appropriate solution.3．Use the best materialsWith all road materials you “pay now or pay later.” Inferior materials may require extensive maintenance throughout the road’s life. They may also force you to replace the road prematurely.Crushed aggregate is the best material for the base course. The sharp angles of thecrushed material interlock when they are compacted. This supports the pavement and traffic by transmitting the load from particle to particle. By contrast, rounded particles act like ballbearings, moving under loads.Angular particles are more stable than rounded particles.Asphalt and concrete pavement materials must be of the highest quality, designed for the conditions, obtained from established firms, and tested to ensure it meets specifications. 4．Compact all layersIn general, the more densely a material is compacted, the stronger it is. Compaction also shrinks or eliminates open spaces (voids) between particles. This means that less water can enter the structure. Water in soil can weaken the structure or lead to frost heaves. This is especially important for unsurfaced (gravel) roads. Use gravel which has a mix of sizes (well-graded aggregate) so smaller particles can fill the voids between larger ones. Goodcompaction of asphalt pavement lengthens its life.5．Design for traffic loads and volumesDesign for the highest anticipated load the road will carry. A road that has been designed only for cars will not stand up to trucks. One truck with 9 tons on a single rear axle does as much damage to a road as nearly 10,000 cars.Rural roads may carry log trucks, milk trucks, fire department pumper trucks, or construction equipment. If you don’t know what specific loads the road will carry, a good rule of thumb is to design for the largest piece of highway maintenance equipment that will be used on the road.A well-constructed and maintained asphalt road should last 20 years without major repairs or reconstruction. In designing a road, use traffic counts that project numbers and sizes of vehicles 20 years into the future. These are only projections, at best, but they will allow you to plan for trafficloadings through a road’s life.6．Design for maintenanceWithout maintenance a road will rapidly deteriorate and fail. Design your roads so they can be easily maintained. This means:• adequate ditches that can be cleaned regularly• culverts that are marked for easy locating in the spring• enough space for snow after it is plowed off the road• proper cross slopes for safety, maintenance and to avoid snow drifts• roadsi des that are planted or treated to prevent erosion• roadsides that can be mowed safelyA rule of thumb for adequate road width is to make it wide enough for a snowplow to pass another vehicle without leaving the travelled way.Mark culverts with a post so they can be located easily.7．Pave only when readyIt is not necessary to pave all your roads immediately. There is nothing wrong with a well-built and wellmaintained gravel road if traffic loads and volume do not require a paved surface. Three hundred vehicles per day is the recommended minimum to justify paving.Don’t assume that laying down asphalt will fix a gravel road that is failing. Before you pave, make sure you have an adequate crushed stone base that drains well and is properly compacted. The recommended minimum depth of crushed stone base is 10" depending on subgrade soils. A road paved only when it is ready will far outperform one that is constructed too quickly.8．Ê Build from the bottom upThis commandment may seem obvious, but it means that you shouldn’t top dress or resurface a road if the problem is in an underlying layer. Before you do any road improvement, locate the cause of any surface problems. Choose an improvement technique that will address the problem. This may mean recycling or removing all road materials down to the native soil and rebuilding everything. Doing any work that doesn’t solve the problem is a waste of money and effort.9．Ê Protect your investmentThe road system can be your municipality’s biggest investment. Just as a home needs painting or a new roof, a road must be maintained. Wisconsin’s severe climate requires more road maintenance than in milder places. Do these important maintenance activities: Surface —grade, shape, patch, seal cracks, control dust, remove snow and iceDrainage —clean and repair ditches and culverts; remove all excess materialRoadside —cut brush, trim trees and roadside plantings, control erosionTraffic service —clean and repair or replace signsDesign roads with adequate ditches so they can be maintained with a motor grader. Clean and grade ditches to maintain proper pitch and peak efficiency. After grading, remove all excess material from the shoulder.10．Keep good recordsYour maintenance will be more efficient with good records. Knowing the road’s construction, life, and repair history makes it much easier to plan and budget its future repairs. Records can also help you evaluate the effectiveness of the repair methods and materials you used.Good record keeping starts with an inventory of the system. It should include the history and surface condition of the roadway, identify and evaluate culverts and bridges, note ditch conditions,shoulders, signs, and such structures as retaining walls and guardrails.Update your inventory each year or when you repair or change a road section. A formal pavement management system can help use these records and plan and budget road improvements.ResourcesThe Basics of a Good Road#17649, UW-Madison, 15 min. videotape. Presents the Ten Commandments of a Good Road. Videotapes are loaned free through County Extension offices.Asphalt PASER Manual(39 pp), Concrete PASER Manual (48 pp), Gravel PASER Manual (32 pp). These booklets contain extensive photos and descriptions of road surfacesto help you understand types of distress conditions and their causes. A simple procedure for rating the condition helps you manage your pavements and plan repairs.Roadware, a computer program which stores and reports pavement condition information. Developed by the Transportation Information Center and enhanced by the Wisconsin Department of Transportation, it uses the PASER rating system to provide five-year cost budgets and roadway repair/reconstruction priority lists.Wisconsin Transportation Bulletin factsheets, available from the Transportation Information Center (T.I.C.).Road Drainage, No. 4. Describes drainage for roadways, shoulders, ditches, and culverts.Gravel Roads, No. 5. Discusses the characteristics of a gravel road and how to maintain one.Using Salt and Sand for Winter Road Maintenance,No. 6. Basic information and practical tips on how to use de-icing chemicals and sand.Culverts—Proper Use and Installation, No. 15. Selecting and sizing culverts, designing, installing and maintaining them.Geotextiles in Road Construction/Maintenance andErosion Control, No. 16. Definitions and common applications of geotextiles on roadways and for erosion control.T.I.C. workshops are offered at locations around the state.Crossroads,an 8-page quarterly newsletter published by the T.I.C. carries helpful articles, workshop information, and resource lists. For more information on any of these materials, contact the T.I.C. at 800/442-4615.中文译文一个良好的公路的基础长久以来我们已经掌握了如何铺设好一条道路的方法，考古学家发现在4600年古埃及使用建造金字塔的石块铺设道路，后来，罗马人使用同样的方法建立了一个庞大的道路系统，这种方法一直沿用到今天。

中英文资料外文翻译文献PavementHighway pavements are divided into two main categories: rigitand flexible.The wearing surfaceof a rigid pavement is usually constructed of Portland cement concrete such that it acts like a beam over any irregularities in the underlying supporting material.The wearing surface of flexible pavements, on the other hand, is usually constructed of bituminous material such that they remain in contact with the underlying material even when minor irregularities occur.Flexible pavements usually consist of a bituminous surface underlaid with a layer of granular material and a layer of a suitable mixture of coarse and fine materials.Coarse aggregatesFine aggregatesTraffic loads are transferred by the wearing surface to the underlying supporting materials through the interlocking of aggregates, the frictionaleffect of the granular materials, and the cohesion of the fine materials.Flexible pavements are further divided into three subgroups: high type, intermediate type, and low type. High-type pavements have wearing surfaces that adequately support the expected traffic load without visible distress due to fatigue and are not susceptible to weather conditions.Intermediate-type pavements have wearing surfaces that range from surface treated to those with qualities just below that of high-type pavements. Low-type pavements are used mainly for low-cost roads and have wearing surfaces that range from untreated to loose natural materials to surface-treated earth.The components of a flexible pavement include the subgradeor preparedroadbed, the subbase, basecourse, and the surface course (Fig.11.1).✹Upper surface courseMiddle surface courseLower surface courseThe performance of the pavement depends on the satisfactory performance of each component, which requires proper evaluation of the properties of each component separately.✹The subgrade is usually the natural material located along the horizontal alignment of the pavement and serves as the foundation of the pavement structure.✹The subgrademay also consist of a layer of selected borrow materials, well compacted to prescribedspecifications.✹Compacting plantCompaction deviceCompactnessIt may be necessary to treat the subgrade material to achieve certain strength properties required for the type of pavement being constructed.Located immediately above the subgrade, the subbase component consists of a superior quality to that which generally is used for subgrade construction. The requirements for subbase materials are usually given in terms of the gradation, plastic characteristics, and strength. When the quality of the subgrade material meets the requirements of the subbase material, the subbase component may be omitted.In cases where suitable subbase material is not readily available ,the available material can be treated with other materials to achieve the necessary properties. This process of treating soils to improve their engineering properties is know as stabilization.✹The base course lies immediately above the subbase. It is placed immediately above the subgrade if a subbase course is not used.✹This course usually consists of granular materials such as crushed stone, crushed or uncrushed.The specifications for base course materials usually include stricter requirements than those for subbase materials, particularly with respect to their plasticity, gradation, and strength.Materials that do not have the required properties can be used as base materials if they are properly stabilized with Portland cement, asphalt, or lime .In some cases, high-quality base course materials may also be treated with asphalt or Portland cement to improve the stiffness characteristics of heavy-duty pavementsThe surface course is the upper course of the road pavement and is constructed immediately above the base course. The surface course in flexible pavement usually consists of a mixture of mineral aggregates and asphaltic materials.It should be capable of withstanding high tire pressures, resisting the abrasive forces due to traffic, providing a skid-resistant driving surface, and preventing thepenetration of surface water into the underlying layers.✹The thickness of the wearing surface can vary from 3 in. to more than 6 in.（inch，英寸，2.54cm）, depending on the expected traffic on the pavement.It was shown that the quality of the surface course of a flexible pavement depends on the mix design of the asphalt concrete used.✹Rigid highway pavements usually are constructed to carry heavy traffic loads, although they have been used for residential and local roads. Properly designed and constructed rigid pavements have long service lives and usually are less expensive to maintain than the flexible pavements.✹The Portland cement concrete commonly used for rigid pavements consists of Portland cement, coarse aggregate, fine aggregate, and water. Steel reinforcing rods may or may not be used, depending on the type of pavement being constructed.Rigid highway pavements be divided into three general type: plain concrete pavements, simply reinforced concrete pavements, and continuously reinforced concrete pavement. The definition of each pavement type is related to the amount of reinforcement used.Plain concrete pavement has no temperature steel or dowels for load transfer. However, steel tie bars are often used to provide a hingeeffect at longitudinal joints and to prevent the opening of these joints. Plain concrete pavements are used mainly on low-volume highways or when cement-stabilized soils are used as subbase.✹Joints are placed at relatively shorter distances (10 to 20 ft) than with the other types of concrete pavements to reduce the amount of cracking.In some case, the transverse joints of plain concrete pavements are skewed about 4 to 5 ft in plan, such that only one wheel of a vehicle passes through the joint at a time. This helps to provide a smoother ride.Simply reinforced concrete pavements have dowels for the transfer of traffic loads across joints, with these joints spaced at larger distances, ranging from 30 to 100 ft. Temperature steel is used throughout the slab, with the amount dependent on the length of the slab. Tie bars are also commonly used in longitudinal joints.h/2 h/25~10cm 填缝料横向施工缝构造Continuously reinforced concrete pavements have no transverse joints, except construction joints or expansion joints when they are necessary at specific positions, such as at bridges.These pavements have a relatively high percentage of steel, with the minimum usually at 0.6 percent of the cross section of the slab. They also contain tie bars across the longitudinal joints.Bituminous Surface CoursesThe bituminous surface course has to provide resistance to the effects of repeated loading by tyres and to the effects of the environment.✹ In addition, it must offer adequate skid resistance in wet weather as well ascomfortable vehicle ride. It must also be resistant to rutting and to cracking.✹ It is also desirable that surface course is impermeable, except in the case ofporous asphalt.Hot rolled asphalt (HRA) is a gapgraded material with less coarse aggregate. In fact it is essentially a bitumen/fine aggregate/filler mortar into which some coarse aggregate is placed.The mechanical propertiesare dominated by those of the mortar. This material has been extensively used as the wearing course on major road in the UK, though its use has recently declined as new materials have been introduced.✹ It provides a durablelayer with good resistance to cracking and one which isrelatively easy to compact. The coarse aggregate content is low (typically 30%) which results in the compacted mixture having a smooth surface. Accordingly, the skid resistance is inadequate and precoated chippings are rolled into the surface at the time of laying to correct this deficiency.In Scotland, HRA wearing course remains the preferred wearing course on trunk roads including motorway but ， since 1999 thin surfacings have been the preferred option in England and Wales. Since 1999 in Northern Ireland, HRA wearing course and thin surfacings are the preferred permitted options.Porous asphalt (PA) is a uniformly graded material which is designed to provide平缝加拉杆型large air voids so that water can drain to the verges within the layer thickness. If the wearing course is to be effective, the basecourse below must be waterproof and the PA must have the ability to retain its open textured properties with time.Thick binder films are required to resist water damage and ageing of the binder. In use, this material minimizes vehicle spray, provides a quiet ride and lower rolling resistance to traffic than dense mixtures.✹It is often specified for environmental reasons but stone mastic asphalt (SMA) and special thin surfacings are generally favoured in current UK practice.There have been high profile instances where a PA wearing course has failed early in its life. The Highways Agency does not recommend the use of a PA at traffic levels above 6000 commercial vehicles per day.✹Asphaltic concrete and dense bitumen macadam (DBM) are continuously graded mixtures similar in principle to the DBMs used in roadbases and basecourses but with smaller maximum particle sizes. Asphaltic concrete tends to have a slightlydenser grading and is used for road surfaces throughout the world with the excepting of the UK.✹It is more difficult to meet UK skid resistance Standards with DBMs than HRA, SMA or PA. This problem can be resolves by providing a separate surface treatment but doing so generally makes DBM economically unattractive.✹Stone mastic asphalt (SMA) material was pioneeredin Germany and Scandinavia and is now widely used in the UK. SMA has a coarse, aggregrate skeleton, like PA, but the voids are filled with a fine aggregate/filler /bitumen mortar.✹In mixtures using penetration grade bitumen , fibres are added to hold the bitumen within the mixture (to prevent “binder drainage”).Bitumen✹oil bitumen( earth oil)✹natural bitumen✹TarWhere a polymer modified bitumen is used, there is generally no need for fibres. SMA is a gap-graded material with good resistance to rutting and high durability. modified bitumen✹SBS✹SBR✹PE\EV A✹It differs from HRA in that the mortar is designed to just fill the voids in the coarse aggregate whereas, in HRA, coarse aggregate is introduced into the mortar and does not provide a continous stone matrix. The higher stone content HRAs ,however, are rather similar to SMA but are not wide used as wearing courses in the UK, being preferred for roadbase and basecourse construction.A variety of thin and what were called ultra thin surfacings (nowadays, the tendency is to use the term …thin surfacings‟ for both thin and ultra thin surfacings )have been introduced in recent years, principally as a result of development work concentrated in France.These materials vary in their detailed constituents but usually have an aggregate grading similar to SMA and often incorporate a polymer modified bitumen.They may be used over a high stiffness roadbase and basecourse or used for resurfacing of existing pavements. For heavy duty pavements (i .e those designed to have a useful life of forty years), the maintenance philosophy is one of minimum lane occupancy, which only allows time for replacement of the wearing course to these …long life‟ pavement structures. The new generation of thin surfa cings allows this to be conveniently achieved.The various generic mixture types described above can be compared with respect to their mechanical properties and durability characteristics by reference to Fig.12.1. This shows, in principle, how low stone content HRA, asphaltic concrete, SMA and PA mixtures mobilize resistance to loading by traffic.Asphaltic concrete (Fig.12.1a)) presents something of a compromise when well designed, since the dense aggregate grading can offer good resistance to the shear stresses which cause rutting, while an adequate binder content will provide reasonable resistance to the tensile stresses which cause cracking.In general, the role of the aggregate dominates. DBMs tend to have less dense gradings and properties which, therefore, tend towards good rutting resistance and away from good crack resistance.HRA (Fig.12.1b)) offers particularly good resistance to cracking through the binder rich mortar between the coarse aggregate particles. This also provides good durability but the lack of coarse aggregate content inhibits resistance to rutting.SMA and PA are shown in the same diagram ( Fig.c)) to emphasis the dominant role the coarse aggregate. In both case, well coated stone is used. In PA, the void space remains available for drainage of water, whilst in SMA, the space is occupied by a fine aggregate/ filler/ bitumen/ fibre mortar.Both materials offer good rutting resistance through the coarse aggregate content. The tensile strength of PA is low whilst that of SMA is probably adequate but little mechanical testing data have been reported to date.Drainage for Road and Airports✹Provision of adequate drainage is important factor in the location and geometric design of road and airports. Drainage facilities on any highway, street and airport should adequately provide for the flow of water away from the surface of the pavement to properly designed channels.Inadequate drainage will eventually result in serious damage to the structure.✹In addition, traffic may be slowed by accumulated water on the pavement, and accidents may occur as a result of hydroplaning and loss of visibility from splash and spray. The importance of adequate drainage is recognized in the amount of highway construction dollars allocated to drainage facilities. About25 percent of highway construction dollars are spent for erosion control anddrainage structures, such as culverts, bridges, channels, and ditches.✹Highway Drainage Structures✹One of the main concerns of the highway engineer is to provide an adequate size structure, such that the waterway opening is sufficiently large to discharge the expected flow of water.Inadequately sized structures can result in water impounding, which may lead to failure of the adjacent sections of the highway due to embankments being submerged in water for long periods.✹The two general categories of drainage structures are major and minor. Major structures are those with clear spans greater than 20 feet, whereas minor structures are those with clear spans of 20 feet or less .✹Major structures are usually large bridges, although multiple-span culverts may also be included in this class. Minor structures include small bridges and culverts.Emphasis is placed on selecting the span and vertical clearancerequirements for major structures. The bridge deck should be located above the high water mark .The clearance above the high water mark depends on whether the waterway is navigable ✹If the waterway is navigable, the clearance above the high water mark should allow the largest ship using the channel to pass underneath the bridge without colliding with the bridge deck. The clearance height, type, and spacing of piers also depend on the probability of ice jams and the extentto which floating logs and debris appear on the waterway during high water.✹An examination of the banks on either side of the waterway will indicate the location of the high water mark, since this is usually associated with signs of erosion and debris deposits. Local residents, who have lived near and observed the waterway during flood stages over a number of years, can also give reliable information on the location of the high water mark. Stream gauges that have been installed in the waterway for many years can also provide data that can be used to locate the high water mark.Minor structures, consisting of short-span bridges and culverts, are the predominant type of drainage structures on highways. Although openings for these structures are not designed to be adequate for the worst flood conditions, they should be large enough to accommodate the flow conditions that might occur during the normal life expectancy of the structure.✹Provision should also be made for preventing clogging of the structure due to floating debris and large boulders rolling from the banks of steep channels.✹Culverts are made of different materials and in different shapes. Materials used to construct culverts include concrete（reinforced and unreinforced）, corrugated steel, and corrugatedaluminum. Other materials may also be used to line the interiorof the culvert to prevent corrosion and abrasionor to reduce hydraulic resistance. For example, asphaltic concrete may be used to line corrugated metal culverts. The different shapes normally used in culvert construction include circular, rectangular (box), elliptical, pipe arch, metal box, and arch.✹The drainage problem is increased in these areas primarily for two reasons: the impervious nature of the area creates a very high runoff; and there is little room for natural water courses. It is often necessary to collect the entire storm water into a system of pipes and transmit it over considerable distances before it can be loosed again as surface runoff. This collection and transmission further increase the problem, since all of the water must be collected with virtually no pending, thus eliminating any natural storage; and through increased velocity the peak runoffs are reached more quickly.Also, the shorter times of peaks cause the system to be more sensitive to short-duration,high intensive rainfall.Storm sewers,like culverts and bridges,are designed for storms of various intensity-return-period relationships, depending uponthe economy and amount of ponding that can be tolerated.✹Airport Drainage✹The problem of providing proper drainage facilities for airports is similar in many ways to that of highways and streets. However, because of the large and relatively flat surface involved, the varying soil conditions, the absence of natural water courses and possible side ditches, and the greater concentration of discharge at the terminus of the construction area, some phases of the problem are more complex. For the average airport the over-all area to be drained is relatively large and an extensive drainage system is required. The magnitude of such a system makes it even more imperative that sound engineering principles based on all of the best available data be used to ensure the most economical design.Overdesigning of facilities results in excessive money investment with no return, and underdesigning can result in conditions hazardous to the air traffic using the airport. In order to ensure surfaces that are smooth, firm, stable, and reasonably free from flooding, it is necessary to provide a system which will do several things.It must collect and remove the surface water from the airport surfaces; intercept and remove surface water flowing toward the airport from adjacent areas; collect and remove any excessive subsurface water beneath the surface of the airport facilities and in many cases lower the ground-water table; and provide protection against erosion of the sloping areas.路面公路的路面被分为两类：刚性的和柔性的。

公路线形设计外文翻译文献(文档含中英文对照即英文原文和中文翻译)Geometric Design of HighwaysA Alignment Designof a road is shown on the plane view and is a series of straight lines called tangents connected by circular. In modern practice it is common to interpose transition or spiral curves between tangents and circular curves.Alignment must be consistent. Sudden changes from flat to sharp curves and long tangents followed by sharp curves must be avoided; otherwise, accident hazards will be created. Likewise, placing circular curves of different radii end to end (compound curves) or having a short tangent between two curves is poor practice unless suitable transitions between them are provided. Long, flat curves are preferable at all times, as they are pleasing in appearance and decrease possibility of future obsolescence. However, alignment without tangents is undesirable on two-lane roads because somedrivers hesitate to pass on curves. Long, flat curves should be used for small changes in direction, as short curves appea r as “kink”. Also horizontal and vertical alignment must be considered together, not separately. For example, a sharp horizontal curve beginning near a crest can create a serious accident hazard.A vehicle traveling in a curved path is subject to centrifugal force. This is balanced by an equal and opposite force developed through cannot exceed certain maximums, and these controls place limits on the sharpness of curves that can be used with a design speed.Usually the sharpness of a given circular curve is indicated by its radius. However, for alignment design, sharpness is commonly expressed in terms of degree of curve, which is the central angle subtended by a 100-ft length of curve. Degree of curve is inversely proportional to the radius.Tangent sections of highways carry normal cross slope; curved sections are super Provision must be made for gradual change from one to the other. This usually involves maintaining the center line of each individual roadway at profile grade while raising the outer edge and lowering the inner edge to produce the desired super is attained some distance beyond the point of curve.If a vehicle travels at high speed on a carefully restricted path made up of tangents connected by sharp circular curve, riding is extremely uncomfortable. As the car approaches a curve, super begins and the vehicle is tilted inward, but the passenger must remain vertical since there is on centrifugal force requiring compensation. When the vehicle reaches the curve, full centrifugal force develops at once, and pulls the rider outward from his vertical position. To achieve a position of equilibrium he must force his body far inward. As the remaining super takes effect, further adjustment in position is required. This process is repeated in reverse order as the vehicle leaves the curve. When easement curves are introduced, the change in radius from infinity on the tangent to that of the circular curve is effected gradually so that centrifugal force also develops gradually. By careful application of super along the spiral, a smooth and gradual application of centrifugal force can be had and the roughness avoided.Easement curves have been used by the railroads for many years, but their adoption by highway agencies has come only recently. This is understandable. Railroad trains must follow the precise alignment of the tracks, and the discomfort described here can be avoided only by adopting easement curves. On the other hand, the motor-vehicle operator is free to alter his lateral position on the road and can provide his own easement curves by steering into circular curves gradually. However, this weaving within a traffic lane (but sometimes into other lanes) is dangerous. Properly designed easement curves make weaving unnecessary. It is largely for safety reasons, then, that easement curves have been widely adopted by highway agencies.For the same radius circular curve, the addition of easement curves at the ends changes the location of the curve with relation to its tangents; hence the decision regarding their use should be made before the final location survey. They point of beginning of an ordinary circular curve is usually labeled the PC (point of curve) or BC (beginning of curve). Its end is marked the PT (point of tangent) or EC (end of curve). For curves that include easements, the common notation is, as stationing increases: TS (tangent to spiral), SC (spiral to circular curve), CS (circular curve to spiral), and ST (spiral go tangent).On two-lane pavements provision of a wilder roadway is advisable on sharp curves. This will allow for such factors as (1) the tendency for drivers to shy away from the pavement edge, (2) increased effective transverse vehicle width because the front and rear wheels do not track, and (3) added width because of the slanted position of the front of the vehicle to the roadway center. For 24-ft roadways, the added width is so small that it can be neglected. Only for 30mph design speeds and curves sharper than 22°does the added width reach 2 ft. For narrower pavements, however, widening assumes importance even on fairly flat curves. Recommended amounts of and procedures for curve widening are given in Geometric Design for Highways.B GradesThe vertical alignment of the roadway and its effect on the safe and economical operation of the motor vehicle constitute one of the most important features of roaddesign. The vertical alignment, which consists of a series of straight lines connected by vertical parabolic or circular curves, is known as the “grade line.” When the grad e line is increasing from the horizontal it is known as a “plus grade,” and when it is decreasing from the horizontal it is known as a “minus grade.” In analyzing grade and grade controls, the designer usually studies the effect of change in grade on the center profile.In the establishment of a grade, an ideal situation is one in which the cut is balanced against the fill without a great deal of borrow or an excess of cut to be wasted. All hauls should be downhill if possible and not too long. The grade should follow the general terrain and rise and fall in the direction of the existing drainage. In mountainous country the grade may be set to balance excavation against embankment as a clue toward least overall cost. In flat or prairie country it will be approximately parallel to the ground surface but sufficiently above it to allow surface drainage and, where necessary, to permit the wind to clear drifting snow. Where the road approaches or follows along streams, the height of the grade line may be dictated by the expected level of flood water. Under all conditions, smooth, flowing grade lines are preferable to choppy ones of many short straight sections connected with short vertical curves.Changes of grade from plus to minus should be placed in cuts, and changes from a minus grade to a plus grade should be placed in fills. This will generally give a good design, and many times it will avoid the appearance of building hills and producing depressions contrary to the general existing contours of the land. Other considerations for determining the grade line may be of more importance than the balancing of cuts and fills.Urban projects usually require a more detailed study of the controls and finer adjustment of elevations than do rural projects. It is often best to adjust the grade to meet existing conditions because of the additional expense of doing otherwise.In the analysis of grade and grade control, one of the most important considerations is the effect of grades on the operating costs of the motor vehicle. An increase in gasoline consumption and a reduction in speed are apparent when grades are increase in gasoline consumption and a reduction in speed is apparent whengrades are increased. An economical approach would be to balance the added annual cost of grade reduction against the added annual cost of vehicle operation without grade reduction. An accurate solution to the problem depends on the knowledge of traffic volume and type, which can be obtained only by means of a traffic survey.While maximum grades vary a great deal in various states, AASHTO recommendations make maximum grades dependent on design speed and topography. Present practice limits grades to 5 percent of a design speed of 70 mph. For a design speed of 30 mph, maximum grades typically range from 7 to 12 percent, depending on topography.Wherever long sustained grades are used, the designer should not substantially exceed the critical length of grade without the provision of climbing lanes for slow-moving vehicles. Critical grade lengths vary from 1700 ft for a 3 percent grade to 500 ft for an 8 percent grade.Long sustained grades should be less than the maximum grade on any particular section of a highway. It is often preferred to break the long sustained uniform grade by placing steeper grades at the bottom and lightening the grade near the top of the ascent. Dips in the profile grade in which vehicles may be hidden from view should also be avoided.Maximum grade for highway is 9 percent. Standards setting minimum grades are of importance only when surface drainage is a problem as when water must be carried away in a gutter or roadside ditch. In such instances the AASHTO suggests a minimum of 0.35%.C Sight DistanceFor safe vehicle operation, highway must be designed to give drivers a sufficient distance or clear version ahead so that they can avoid unexpected obstacles and can pass slower vehicles without danger. Sight distance is the length of highway visible ahead to the driver of a vehicle. The concept of safe sight distance has two facets: “stopping” (or “no passing”) and “passing”.At times large objects may drop into a roadway and will do serious damage to amotor vehicle that strikes them. Again a car or truck may be forced to stop in the traffic lane in the path of following vehicles. In dither instance, proper design requires that such hazards become visible at distances great enough that drivers can stop before hitting them. Further more, it is unsafe to assume that one oncoming vehicle may avoid trouble by leaving the lane in which it is traveling, for this might result in loss of control or collision with another vehicle.Stopping sight distance is made up of two elements. The first is the distance traveled after the obstruction comes into view but before the driver applies his brakes. During this period of perception and reaction, the vehicle travels at its initial velocity. The second distance is consumed while the driver brakes the vehicle to a stop. The first of these two distances is dependent on the speed of the vehicle and the perception time and brake-reaction time of the operator. The second distance depends on the speed of the vehicle; the condition of brakes, times, and roadway surface; and the alignment and grade of the highway.On two-lane highways, opportunity to pass slow-moving vehicles must be provided at intervals. Otherwise capacity decreases and accidents increase as impatient drivers risk head-on collisions by passing when it is unsafe to do so. The minimum distance ahead that must be clear to permit safe passing is called the passing sight distance.In deciding whether or not to pass another vehicle, the driver must weigh the clear distance available to him against the distance required to carry out the sequence of events that make up the passing maneuver. Among the factors that will influence his decision are the degree of caution that he exercises and the accelerating ability of his vehicle. Because humans differ markedly, passing practices, which depend largely on human judgment and behavior rather than on the laws of mechanics, vary considerably among drivers. To establish design values for passing sight distances, engineers observed the passing practices of many drivers. Basic observations on which passing sight distance standards are based were made during the period 1938-1941. Assumed operating conditions are as follows:1.The overtaken vehicle travels at a uniform speed.2.The passing vehicle has reduced speed and trails the overtaken one as it entersthe passing section.3.When the passing section is reached, the driver requires a short period of timeto perceive the clear passing section and to react to start his maneuver.4.Passing is accomplished under what may be termed a delayed start and ahurried return in the face of opposing traffic. The passing vehicle accelerates during the maneuver and its average speed during occupancy of the left lane is 10 mph higher than that of the overtaken vehicle.5.When the passing vehicle returns to its lane there is a suitable clearancelength between it and an oncoming vehicle in the other lane.The five distances, in sum, make up passing sight distance.公路线形设计A 平面设计道路的线形反映在平面图上是由一系列的直线和与直线相连的圆曲线构成的。

附录A 外文翻译原文Road DesignHistory of Road DesignFirstly let me apologise for this page. It is largely text based due to the nature of it and if reading is difficult then I am sorry. This is due solely to the material covered and is the only page in the series. This is not typical as the rest have graphics or images to keep you amused. Secondly this page is very much a history of road building in the United Kingdom．The first road builders of any significance in Western Europe were the Romans, who saw the ability to move quickly as essential for both military and civil reasons. It is from the Romans that the term highway comes as all their roads were elevated 1m above the local level of the land. This was to minimise the risk of an ambush, as was the best known characteristic of the roads, their lack of corners. The standards set by the Romans in terms of durability far exceeded anything achieved after the fall of the empire.The Roman approach to road design is essentially the same as that in current use. The roads were constructed of several different layers, increasing in strength from the bottom. The lowest layer was normally a rubble, intermediate layers were made of lime bound concrete and the upper layer was a flag or lime grouted stone slabs. The thickness of the layers was varied according to the local ground conditions.After the fall of the Roman Empire the road system fell into a state of disrepair and by the end of the middle ages, there was in effect no road system in the country. The only routes available were unpaved tracks, muddy and impassable in winter and dusty and impassable in summer. Diversions around particularly poor stretches resulted in sinuous alignments. The state of the roads combined with the general lawlessness at the time meant only the determined or insane traveled.The first change in this attitude came in 1555 when an Act of Parliament was passed imposing a duty on all parishes to maintain it's roads. Also included in the Act was the creation of the position of a Surveyor of Highways. This was unpaid and under resourced though and when combined with the lack of technical skills it is no surprise that the post became distinctly unpopular and ineffective.This lack of resources meant that the first major road was not established until the latter part of the seventeenth century. These roads were known as turnpike roads where the road user paid a toll. The first sections were known as the Great North Road and has since become the A1 trunk road. In the following century Turnpike Trusts were established to provide turnpike roads along major routes in the United kingdom. In this improved financial climate roadbuilding techniques evolved thanks to the work of pioneers such as Telford and Macadam. By about 1830 a system of well paved built roads existed such that the only constraints on road traffic and travel times were imposed by the nature of road vehicles.The next improvement came about with the advent of the railways. With rapid transport between towns now possible, the turnpikes became uneconomical and whilst roadbuilding in towns continued apace the turnpike trusts collapsed. Legislation in the late 19th century set the scene for the current administrative arrangements for highway construction and maintenance but the technology remained primitive and empirical. Only in recent years has that situation improved to any extent and even now most road design is based on empirical relationships and experimental work.The present situation is almost a complete reversal, with funding for new roads coming from the private sector. In exchange for building and maintaining the road the owners are paid a toll by the government for each vehicle using the road, a sort of modern turnpike system.Traffic AnalysisRoad loading takes many different forms, from a bicycle to multi-axled truck and trailer combinations.Traffic Analysis can be split into two well defined areas:Traffic Volume - This is the role of the Traffic Engineer and does not normally concern the Civil Engineer. This is not relevant to determining the load on the road, only the size and layout.Traffic Loading -This is the role of the Pavement Engineer and involves determining the loading on the road to be carried forward to the Pavement Design. Traffic V olumeThe role of the traffic engineer is to enable all traffic to travel on the road at a reasonable speed and with an appropriate degree of safety. This is not the loading that is used in the Pavement Design. These values are used to determine the road width only.With relation to the volume of traffic using the road, the passenger car is adopted as the standard unit and other vehicles are assessed in terms of passenger car units (pcu).Differences in the urban and rural situations arise due to the variation of speeds in the two areas. Decisions on road width are not normally made on total traffic flow per day as this is misleading but rather on the peak hourly flow. In Britain the maximum permissible flow is 3,000 pcu/h for a two lane dual carriageway and 4,500 pcu/h for a three lane dual carriageway (motorway). For all purpose roads with junctions these figures reduce to 1,100 ｀｀and 1,900 pcu/h respectively.Where the road is new, studies must be carried out to estimate the volume of traffic expected to use the road. Where the new road replaces existing roads this is not too difficult. If however the road is expected to change the flow of traffic then analysis should be carried out as to the volume and constitution of traffic on the new road. Matters are further complicated if the road is very long or provides access to or from a large town. Computer methods are now available to aid in this process. The constitution of traffic on the new road is of interest to the pavement engineer. Traffic LoadingIn this section, we will discuss the traffic loading that is taken forward to the pavement design section. Unlike in the above section where Passenger Car Units were the reference unit, we will work in Standard Axles. This is a reference unit to determine the average loading on a pavement by what is known as the standard axle. This then allows a total loading over the life of the pavement to be determined, normally in Millions of Standard Axles (msa).EarthworksThe Process of earthworks is to excavate the existing land to a suitable level so that road construction may begin. The earthworks can take the form of either excavation in the form of cuts or the construction of embankments to carry anelevated highway. Normally in a road design project, both will be necessary and movement of earth from one part of the site to the next will be necessary. This should be done with as little waste created or as little extra material required as disposal or collection is expensive.Also included under the topic of earthworks is the compaction of the road materials to the appropriate level. This however is not covered as it is more concerned with the actual construction of the road than the design of it.This page is concerned solely with the design of the earthworks and not with the actual design of the embankments or cuts. If you wish to learn more about this then links to relevant pages are contained in the geotechnical section of the links page. A link to this can be found opposite.Of the topics covered in this page, they can be split up into the design of the earthworks and the plant used in the construction.ExcavationThe most important feature of the excavation is the material you are working with. This will be known from the Site Investigation. Poor information can lead to technical problems and to cost overruns.There are many ways of classifying the soil in terms of it's ease of excavation including seismic techniques. The most common in the United Kingdom at present however is the Ease of Digging scale or diggability. This classifies the soil in one of four categories:E Easy digging - Loose free running soils eg sands, fine gravels.M Medium - Denser cohesive soils eg clayey gravel, low PI clays .M-H Medium to Hard - eg broken rock, wet heavy clay, gravel with boulders.H Hard - material requiring blasting and hard high PI clays.Typical diggability factors can be seen in Table 1 below.Another important feature of rock is the amount of fissuring. There are two methods of assessing this, the percentage Rock Quality Data method and the Spacing of joints method. Each of these leads directly to an estimate of the uniaxial compressive strength and thus an indication of the excavation method. Both these can be found in the Manual of contracts document, Series 6001.Excavation increases the volume of material. It is therefore necessary to use a bulking factor to determine the volume of material that will be created by excavation. Bulking factor is defined as:Bulking Factor = V olume after Excavation/V olume before Excavation Similarly a shrinkage factor is defined for the compaction of a soil at it's final destination.:Shrinkage Factor = V olume after Compaction/V olume before Excavation In addition to the above properties, it is important to have some idea about the trafficability of the soils. This is because the excavation plant will need to drive over the soils without becoming bogged down. The trafficability of the soils is related to their drainage properties.Sands/GravelsFree Draining. Tend to have few problems.High PI ClaysLow permeability will prevent water ingress so the surface becomes dangerous but not in the long term.Silts/Low PI ClaysThese cause the most problems. Permeability allows ingress which softens the soils thus weakening them.Asphalt Paving OperationIntroductionThe subject of this term project was an asphalt paving process utilizing a paving machine and 20 tons capacity tri-axle trucks. The location of the process was at the corner of Main and Madison in Greenwood ( South of Indianapolis ). The project is being run by the Reith-Riley Construction Company. - Indianapolis. The overall process involved :1.Hot-mix batch plant cycle2.Tri-axle truck cycle3.Roller cycle4.Spreader cycle5.Crew cycleBecause of the complexity of the overall construction process, we chose to observe, report on, analyze and model the paving process on the base layer of the 15' lane road. At that time, the other lane of the road was not paved yet. The road has slightly increasing grade and curve along the process. The preliminary process of gathering the data used in this project, the efficiency of the operation, a model and MicroCYCLONE simulation of the process, and illustrations will be discussed and presented.Asphalt has been used by man for its adhesive and waterproofing properties. Asphalt was used in 3800 B.C. in the Euphrates and 2500 B.C. in Egypt. The Sumerians used asphalt in 6000 B.C. for its shipbuilding industry. Today, asphalt is applied to roofing, sealants, caulking, brake linings, paints, enamels, and most widely used in the paving industry (Asphalt - Science and Technology, 1968).Process DescriptionBatch Plant ProductionFirst, aggregate travels through the cold feed bins, where initial proportioning of the aggregate takes place. The quantity of material leaving each bin is regulated by the size of the gate opening, or the speed of a belt, or a combination of the two. The aggregate is sent to a drier. Here the moisture is removed and is heated to provide the proper mixing temperature in the pugmill. The aggregate continues to the hot elevator by screens to the hot bins. The screens provide the final separation of the aggregate.The different sizes of aggregate are released into the weight hopper one bin at a time. The aggregate is dropped into the pugmill for mixing with the asphalt. The mixture is then dropped into a waiting truck or moved to a storage silo. Samples are taken from each hot bin for testing. A sieve analysis is conducted as well as gradation test. From the gradation information, the weight of the aggregate must be equal to the design gradation. A trial run should be performed and the weights adjusted until the desired mix is produced. (U.S. Department of Transportation, December 1984) The different sizes of aggregate are released into the weight hopper one bin at a time. The aggregate is dropped into the pugmill for mixing with the asphalt. The mixture is then dropped into a waiting truck or moved to a storage silo. Samples aretaken from each hot bin for testing. A sieve analysis is conducted as well as gradation test. From the gradation information, the weight of the aggregate must be equal to the design gradation. A trial run should be performed and the weights adjusted until the desired mix is produced. (U.S. Department of Transportation, December 1984) Placing Asphalt PavementPlacing the CoatBefore the paving operation starts, an asphalt distributor is used to spray asphalt on the unpaved surface. This film of asphalt serves as the prime and tact coats. The coats are then allowed to cure before the actual paving resume. The purpose of having these coats is to prevent any slippage between the surface and overlay during or after the compaction. (The Asphalt Institute)Placing the Asphalt MixTo start the paving operation, the paver is positioned properly onto the road. The screed of the paver is lowered onto block of the same depth of the loose asphalt mat that is going to be laid on the road. (The screed is responsible for the setting the depth of the asphalt mix.) After that, the block can be removed and paving can start. As soon as the haul truck arrives at the job site, the paving inspector must check that the asphalt delivered must be in a satisfactory condition. The paving inspector usually check for these criteria listed below:1.blue smoke - blue smoke indicate that the mix is too hot.2.stiff appearance3.mix slumped in truck.4.lean, dull appearance - this indicates that the mix has insufficient asphalt.5.rising steam - too much moisture.6.segregation.7.contamination.If there is any of the signs above is observed, the mix will be sent back to the batch plant to be reprocessed. After all conditions are satisfied, the haul truck can load the mix into the receiving hopper of the paver.When loading the mix into the receiving hopper, the haul truck is placed carefully in front of the paver. The rear wheels of the truck should be in contact withthe truck roller of the paver to avoid any misalignment with the paver. The paver will push the truck forwards as it paves the road. If skewness happens, the whole process will be delayed because they have to reposition the truck in front of the paver.Most paver used are self-propelled paver. Each of them consists of two main units:Tractor unit. -it includes the receiving hopper, slot conveyor, flow control gates, spreading crew, power plant, transmission, operator control for use on either side, and operator's seat. This unit will move the whole system forward.Screed unit. -it is attached to the tractor unit by long screed arms on both sides of the machine. It consists of screed plate, vibrators or tamper bars, thickness control, crown control, and screed heater.As soon as the the first load of asphalt mix has been spread, the uniformity of the asphalt texture should be checked. Operators will adjust the the appropriate adjustment points to correct any nonuniformity. Any segregation of materials also should not be allowed. Operation should be stopped immediately if any segregation is detected. The operators should also be aware of is the crown control. Pavement with crown has to be redone all over again. In addition to that, operators should continuously loosen the mix that clings to the sides of the hopper and push it back into the active mix. If the asphalt mix grow cold, it cannot be properly compacted and thus, looses its strength.The last process of paving is compaction. This process is highly influenced by major mix proportion; (1) asphalt content: aggregate size, shape texture and distribution gradation; (2) filler content, and; (3) mix temperature. Appropriate rollers and rolling methods should be used in accordance with these proportion. There are several roller combinations used for maximum results:1.steel-tired static and pneumatic-tired rollers,2.vibratory and steel-tired static rollers, or3.vibratory rollers used in vibrating and static modes.4.These combinations are highly recommended by the asphalt institute.Rollers should be moved in a slow but uniform speed to achieve the best result. (See table) These rollers should also be in good conditions. Any irregularities in therollers' performances will result in poor compaction of the asphalt; thus, the pavement will not last long. The rollers should not reverse suddenly while compacting because this action can displace the mix. If displacement happens, the whole mat should be loosened with lutes or rakes and restored to the original grade before rolling can restart. A pattern that is economical and provides the maximum compaction result should be established. (The Asphalt Institute)Testing MethodWhy Evaluate Density of Hot Asphalt ConcreteAs we know, lacking of density during construction of asphalt concrete causes many problems. It is necessary to obtain high density to insure that the asphalt concrete will provide the necessary stability and durability for performance. For instance, low density generally causes long-term deterioration when the asphalt begins cracking. Therefore various methods have been used to measure the density in the asphalt concrete.Procedures Used to Obtain DensityProper aggregate gradation and asphalt content are important parameters to ensure that the density of asphalt concrete meets the requirement. Generally, poor gradation results in a reduction of voids in the mixture; thus, reduces the asphalt content which serves as the lubricant for aggregates in the mix. The stiff mix is more difficult to compact. Both the aggregate gradation and the asphalt content are interrelated and equally important.Paving asphalt is really difficult in cold climate. The hot mix cools down faster and harder to compact. To overcome this, contractors usually increase the temperature of the mix. Unfortunately excessively increasing the temperature of asphalt mixture may cause problems during compaction and increase oxidation of the asphalt cement. This may result in a hard and brittle pavement. The mix temperature should be selected so that the mixture would be able to support the roller immediately behind the paver. Since there is less time to roll the mixture before it cools, more rollers or larger rollers are required for the compaction process.After the mixture is transported to the site, the next step is to ensure proper density while laying down the asphalt with a spreader. A continuos availability of theasphalt mix for the paver is crucial. The spreader cannot afford to start and stop while waiting for the materials. It important to have material that has the same texture and appearance.Evaluation of In-Place DensityAn evaluation of the in-place material is necessary to ensure that a satisfactory density is obtained. Most of the time, a nuclear gage is used to estimate the density. However, the results obtained using this equipment are not accurate. It has to be calibrated by taking a number of measurements from different location as soon as the project starts. After calibrations, a series of readings are taken and then, the readings are compared to the density obtained from the laboratory. The laboratory results are the density of core samples taken from the same location. (Placement and Compaction of Asphalt Mixtures, 1982)Laboratory and Field Pavement Stability TestsThe American Association of State Highway Officials (AASHO) and the American Society for Testing and Materials (ASTM) are two agencies which set forth methods and test procedures the paving industry must follow. Five test methods readily used in the field and laboratory are:1.The Hubbard Field Stability Test (ASTM-D-1138-52 or AASHO Test 169) - tests the resistance to plastic flow of fine aggregate mixtures.2.The Unconfined Compression Test (ASTM-D-1074-52-T) - measures the cohesion of paving binder and performance of the internal friction of the aggregate.3.The Marshall Test (ASTM-Method-D-1559) - measures the flow value or flow index by distorting the specimen until fracture.4.The Hveem Test (ASTM-Method-1560) - uses stabilometer and cohesiometer apparatus. The stabilometer determines the maximum amount of asphalt which will obtain the greatest stability by measuring the internal fiction of the mineral aggregate. The cohesiometer determines the cohesion properties and the strength of asphalt films by bending and breaking a specimen.5.The Triaxial Compression Test - is useful in determining the cohesion of the mix and asphalt contents and the angle of internal friction of the entire mixture by applying lateral pressures. Theses are the most widely used although a variety ofother methods exist. It must be stated that different local, state, and federal organizations will require certain tests to be performed and may accept adifferent range of values.Resources DescriptionMaterial:1.Aggregates2.Hot mix asphalt materialEquipment:1.Trucks2.Spreader3.RollerBatch plant (hot mix)Laborer :1 laborer1 roller operator1 paver operator1 superintendent1 truck operators1 foremanDiscussionDiscussion Preliminary Procedure to Obtain DataInitially contacting the company and project engineers involved was necessary before we could obtain access to the site and accumulate data and information about the operation. Dan Patrick, the superintendent of Reith-Riley Construction, provided general information regarding this operation. This included cost ( by providing us with the Company's Job Calculation Sheet ), specific details concerning the operation described and modeled in this paper and details of the crew sizes, equipment, materials, efficiency and variables of the operation. The site was visited often to observe and obtain the details of the operation. Pictures were taken, and individual questioning of the crews and inspector involved in the plant and job site were employed to get an accurate idea and necessary data. Mr. Patrick couldn't provide apool data regarding production times. We were given an estimate of schedule of the job calculation sheet which were used to compare with the observed/actual production.Data CollectionThe general description of the project, the process involved, and the equipment used was obtained from Dan Patrick, the superintendent of Reith-Riley Construction.The actual project site and time duration for each activities were obtained from field observation on October 9th, 1991. A digital watch was used to time every activities involved in the process. The data collected were averaged for the ease of calculation. The data include the average for :1.loading at batch plant2.travelling to the job site3.dumping the asphalt to spreader4.back-cycle of the truck5.spreading the asphaltpacting the asphalt7.checking the levelAll the data obtained were approved by the superintendent as standard time for this particular paving operation. This information is listed in table 1. The high and low data in table 2.1 and 2.2. were given by the superintendent. Therefore, the average values of the deterministic input were used as the mode values for the Triangular and Beta distribution. The Beta 'a' and Beta 'b' values were calculated by the Vibes program.Material Handling and Processing System1.Loading hot mix asphalt to the truck2.Hauling asphalt to job site3.Dumping the asphalt to the spreader4.Spreader paving the asphalt5.Roller breaking down the asphalt6.Roller finishing the surfaceProductivity ComparisonThe productivity level can be measured in three different ways1.Deterministic time2.Triangle distribution3.Beta DistributionThe values for all three methods were closely related (table 3.). Generally the deterministic values were higher while Beta values were lower. Triangle values were located somewhere in between the aforementioned. The range of differences between the distribution is 0.0289 to 0.4278. These difference were not significant; therefore, any distribution could be used in an actual situation. The production values from Beta distribution were used for determining the theoretical productivity because they were more conservative.From the company's Job Calculation Sheet, they estimated the capacity of the truck to be 20 tons and working 30 cycles per day. The company's estimated productivity is 600 tons per day which was equal to 3.75 truck-loads per hour. Refer to table 3 for comparison of productivity. The productivities of the simulated result of the MicroCYCLONE model were found to be a little bit lower. The percentage differences as given in table 3 were as followed :pared with deterministic time : 4.67 %pared with Triangle distribution time : 10.78 %pared with Beta distribution time : 12.87 %Improvement of ProductivityUsing sensitivity analysis, the productivity of the whole asphalt paving operation could be increased by adding one more roller. With only one roller, the deterministic productivity at cycle 30 was 3.575 truck-loads per hour. By adding the second roller, the productivity was increased to 6.4632 truck-loads per hour. The productivity was increased by about 81 %. ( look at appendix for the output files ).Also the sensitivity analysis showed that increasing truck did not increase the productivity at all.ConclusionThe rate of the operation was determined by the rate of the roller. This was because the roller took 15 minutes to compact the surface of the asphalt. Thus, toimprove the productivity, more roller should be added into the operation. Nevertheless, the company chose to use only one roller. Perhaps, the decision to only have one roller was determined by cost factor. The productivity obtained from the MicroCYCLONE model was within the expected productivity by the company. References1.Barth, Edwin J., "Asphalt-Science and Technology," Gordon and Breach, New York, New York, 1986.2.Wagner, F.T., "Placement and Compaction of Asphalt Mixture," ASTM Publication, Philadelphia, PA 19103.3.The Asphalt Institute, "Asphalt Paving Manual," Manual Series No. 8, Third Edition, April 1988.4.U.S. Department of Transportation, Federal Highway Administration, "Hot-Mix Bituminous Paving Manual," December 1994.5.Personal interview with Reith Riley Construction Company Indianapolis, Job Superintendent: Mr. Dan Patrick, October , 1991.附录B 外文翻译译文道路设计道路设计的历史首先,让我对本栏目作一介绍。

Words and ExpressionsFor Station and Yard Design1.线路设计track design2.平面设计plane design3.纵断面设计longitudinal section design4.横断面设计transverse section design5.曲线设计curve design6.车站设计station design7.站场设计design of stations and yards8.线路等级line grade9.铁路限界railway clearance10.建筑限界construction clearance11.铁路曲线railway curve12.缓和曲线transition curve; easement curve; spiral transition curve13.小半径曲线small-radius curve14.曲线半径curve radius15.曲线超高superelevation on curve; cant; elevation of curve16.欠超高inadequate superelevation; deficient superelevation17.竖曲线vertical curve18.坡道gradient19.坡度grade; gradient; slope20.限制坡度ruling grade; limiting grade21.坡度折减grade compensation; compensation of gradient; gradient compensation22.避难线refuge siding; catch siding23.双线插入段double track interpolation24.警冲标fouling point indicator; fouling post25.线路中心线track center line; central lines of track26.线间距distance between centres of lines; distance between centers of tracks; midway between tracks27.道岔switch; point; turnout; switches and crossings28.单开道岔single point; simple turnout; lateral turnout29.双开道岔double turnout30.三开道岔three-throw turnout; symmetrical three throw turnout; three-way turnout31.交分道岔slip switch32.交叉crossing33.渡线track cross-over; crossover34.通过道岔passing switch35.铁路道口railway crossing36.平交道口level crossing37.立体交叉; 立交grade separation38.机车车辆检修rolling stock inspection and repair39.机务部门locomotive department40.机务段locomotive depot41.机务段设备locomotive depot appliance42.车辆段car depot43.车辆段设备car depot appliance44.检修段inspection and repair depot45.车库shed; car shed46.机车库locomotive shed47.列检所train inspection and repair point48.修理厂repair shop49.铁路站场railway station and yard50.车站等级classification of station; class of station51.车站改编能力sorting capacity at station52.站场配置图layout plan of station and yard53.车站咽喉station bottleneck; station throat54.进路疏解route untwine55.车站改建reconstruction of station56.驼峰设计hump design57.溜放阻力free rolling resistance58.驼峰作业能力humping capacity59.车站station60.枢纽站terminals61.区段站district station62.中间站intermediate station63.会让站crossing station; passing station64.港湾站port station; harbor station65.换装站国境站; 换装站frontier station66.客运站passenger station67.换乘站transfer station68.线路所; 乘降所passenger stopping point; halt69.货运站freight station70.工业站industria l station71.集装箱站container station72.换装站transshipment station73.编组站marshalling station; marshalling yard74.驼峰编组站hump marshalling station75.站舍station building76.高架站舍; 高架车站elevated station building77.站台platform78.车场car yard79.到达场receiving yard; arriving yard80.到发场reception-departure yard; receiving-departureyard81.出发场departure yard82.车站配线; 站线station track; station line83.到发线reception-departure track; arrival and departuretrack84.到达线arrival track; receiving track; arriving track85.出发线departure track86.编组线sorting track87.牵出线shunting neck; switching lead; lead track88.机车走行线locomotive running line; locomotive runningtrack89.装卸线loading and unloading track90.换装线transshipment track91.尽头线stub-end track; stub-end siding92.码头线dock line93.安全线safety siding; catch siding94.客运站设备equipment of passenger station95.旅客站台passenger platform96.广场square97.候车室waiting hall; waiting room98.问询处inquiry office99.行包房luggage and parcel office100.天桥passenger foot bridge; over-bridge; passenger foot-bridge101.地道underground gallery; underground path102.雨棚rain shed103.客车整备场passenger car servicing depot104.货运站设备goods station equipment105.货物站台good platform; freight platform; goods platform 106.货场freight yard; goods yard107.集装箱货场container yard1108.仓库storage; warehouse109.自动化仓库automatic warehouse110.货位goods allocation; fre ight section; goods section 111.货棚freight shed; goods shed112.编组场调车场; 编组场shunting yard; marshalling yard; classification yard113.溜放线free rolling line114.驼峰hump115.机械化驼峰mechanized hump116.半自动化驼峰semi-automatic humpWords and ExpressionsFor Railway Operation1.编组站管理系统marshalling station management system2.货运管理系统freight traffic management system3.集装箱管理系统container management system4.客运管理系统passenger traffic management system5.客票预售系统ticket reservation system6.电子数据交换electronic data interchange7.保温运输insulated transport8.备用货车reserved cars9.本站作业车local car10.变更径路route diversion11.不成对运行图train diagram not in pairs12.不同时到达间隔时间time interval between two opposing trains arriving13.场库storage yard and warehouse14.敞顶集装箱open top container15.超长货物exceptional length freight16.超限货物o ut-of-gauge freight17.超限货物等级classification of out-of-gauge freight18.超限货物检查架examining rack for out-of-gauge freight19.车钩缓冲停止器device for stopping buffer action20.车辆换算长度converted car length21.车流径路car flow route22.车票有效期ticket availability23.车站班计划station shift operating plan24.车站办理车数number of inbound and outbound car handled at stat25.车站工作组织organization of station operation26.车站技术作业表station technical working diagram27.车站阶段计划station stage operating plan28.车站行车工作细则instructions for train operation at station29.车站咽喉通过能力carrying capacity of station throat30.车站作业计划station operating plan31.成对运行图train diagram in pairs32.成件包装货物packed freight33.成组装车car loading by groups34.冲突collision35.存车线storage siding36.大事故serious accident37.大修计划plan of capital repair38.大宗货物mass freight39.代用票substituting ticket40.单面托盘single-deck pallet41.单线运行图train diagram for single track42.单向横列式编组站uni directional transversal type marshalling station43.单向混合式编组站uni directional combined typemarshalling station44.单向纵列式编组站unidirectional longitudinal typemarshalling station45.挡车器stop buffer46.到达路destination railway47.到发线通过能力carrying capacity of receiving-departuretrack48.道岔绝缘段insulated switch section49.道岔配列switch layout50.道岔清扫房switch cleaners cabin51.道岔区坡gradient within the switching area52.道岔阻力switch resistance53.敌对进路conflicting routes54.地方性编组站local marshalling station55.点连式调速系统point-continued type speed controlsystem56.点式调速系统point type speed control system57.调车进路shunting route58.调车设备marshalling facilities59.调车线shunting track60.调车作业计划shunting operation plan61.调度命令traffic dispatching order62.调度区段train dispatching section63.调度日班计划daily and shift traffic plans64.定期票periodical ticket65.丢失事故loss accident66.冻结货物frozen freight67.段管线depot siding68.堆货场storage yard69.堆码能力stacking capability70.堆码作业stacking operation71.堆装货物stack-loading freight72.鹅颈槽goose neck tunnel73.发车进路departure route74.发送路originating railway75.反向行车train running in reverse direction76.非机械化驼峰non-mechanized hump77.非平行运行图non-parallel train diagram78.非营业站non-operating station79.非运用车non-serviceable car80.分号运行图variant train diagram81.分界点train spacing point82.分类折旧率classified depreciation rate83.封闭式通风集装箱closed ventilated container84.封锁区间closing the section85.峰顶hump crest86.峰顶调车员室shunters cabin at hump crest87.峰顶平台platform of hump crest88.峰高计算点calculate point of hump height89.辅助编组站auxiliary marshalling station90.辅助车场auxiliary yard91.辅助所auxiliary block post92.腐坏事故decay acci dent93.干散货集装箱dry bulk container94.高架候车厅overhead waiting hall95.告警信号warning signal96.更新改造计划plan of renewal and upgrading97.公用乘车证service pass98.钩车cars per cut299.固定资产残值scrap value of fixed assets100.固定资产大修capital repair of fixed assets101.固定资产更新改造renewal and reconstruction of fixed assets102.固定资产更新率rate of fixed assets renewal103.固定资产投资fixed asset investment104.固定资产退废率rate of fixed assets retirement105.固定资产原价original value of fixed assets106.关闭信号closing signal107.管内工作车local cars to be unloaded108.管内客流local passenger flow109.管内旅客列车local passenger train110.管内装卸率local loading and unloading rate111.灌装货物tank car freight112.广厅public hall113.轨道衡线weight bridge track114.国际货物联运international through freight traffic 115.国际联运货物换装transshipment of international through goods116.国际联运货物交接单acceptance and delivery list of freight for intern117.国际联运货物票据international through freight shipping documents118.国际联运旅客车票passenger ticket for international through traffic119.国际联运旅客特别快车international express train 120.国际联运站international through traffic station121.国际铁路货物联运协定agreement of international railway through freight122.国际铁路协定agreement of frontier railway123.过境路transit railway124.横列式区段站transversal type district station125.环线loop126.环形枢纽loop-type junction terminal127.换算吨公里成本cost of converted ton-kilometer128.换算周转量converted turnover129.恢复通车restoring traffic130.会车间隔时间time interval for two meeting trains at station131.混合式货场mixed-type freight yard132.混合形枢纽combined type junction terminal133.货差率mistake rate of goods134.货车标记载重量marked loading capacity of car135.货车动载重dynamic load of car136.货车检修率ratio of freight cars under repair137.货车静载重static load of car138.货车溜放风阻力rolling car resistance due to wind effects 139.货车溜放基本阻力basic rolling car resistance140.货车日产量serviceable work-done per car day141.货车日车公里car kilometers per car per day142.货车施封car seal143.货车载重量利用率coefficient of utilization for car loading capacity144.货车中转距离average car kilometers per transit operation145.货车周转距离average car kilometers in one turnaround 146.货车装载清单car loading list147.货垛stack of freight148.货流量freight flow volume149.货损率damage rate of goods150.货物标记freight label151.货物承运acceptance of freight152.货物换装整理transshipment and rearrangement of goods 153.货物计费重量charged weight154.货物交接所freight transfer point155.货物列车编组计划freight train formation plan156.货物品类goods category157.货物途中作业freight operation en route158.货物运到期限freight transit period159.货物运价号freight tariff no.160.货物运价里程tariff kilometerage161.货物运价率freight rate162.货物运输变更traffic diversion163.货物运输计划freight traffic plan164.货物运输量freight traffic volume165.货物运输系数coefficient of freight traffic166.货物运送吨数tonnage of freight transported167.货物重心的横向位移lateral shift for center of gravity of goods168.货物重心的纵向位移longitudinal shift for center of gravity of goods169.货运波动系数fluctuating coefficient of freight traffic 170.货运经济调查economic investigation of freight traffic 171.货运杂费miscellaneous fees of goods traffic172.机车车辆溜逸runaway of locomotive or car173.机车车辆破损rolling stock damage174.机车车辆运用计划rolling stock utilization plan175.机车检修率ratio of locomotives under repair176.机车能耗locomotive energy consumption177.机待线locomotive waiting track178.基本建设计划plan of capital construction179.基本建设投资capital construction investment180.基本票价basic fare181.基本运行图primary train diagram182.基本折旧率basic depreciation rate183.集结时间car detention time under accumulation184.集重货物concentrated weight goods185.集装箱额定质量rating of freight container186.集装箱载重payload of freight container187.集装箱自重tare mass of freight container188.计费吨公里ton-kilometers charged189.计费吨公里成本cost of charged ton-kilometer190.计划内运输planned freight traffic191.计划外运输out-of-plan freight traffic192.技术站technical station193.技术直达列车technical through train194.加冰所re-icing point195.加快票fast extra ticket196.加热集装箱heated container197.加速坡accelerating grade198.加温运输heating transport199.间隔制动spacing braking200.减价票reduced-fare ticket201.减速器retarder202.减速器出口速度release speed at retarder203.减速器入口速度entrance speed at retarder204.简易驼峰simplified hump205.箭翎线herringbone track3206.交叉疏解crossing untwining207.交出空车数number of empty cars delivered208.交出重车数number of loaded cars delivered209.接车进路receiving route210.接发列车train reception and departure211.接入空车数number of empty cars received212.接运重车数number of loaded cars received213.尽端式枢纽stub-end type junction terminal214.尽头式货场stub-end type freight yard215.尽头式货运站stub-end freight station216.尽头式客运站stub-end passenger station217.进路交叉crossing of routes218.经济效果economic effects219.救援机车breakdown locomotive220.救援起重机wrecking crane221.绝热集装箱insulated container222.开放信号clearing signal223.可控减速顶controllable retarder224.客车客座利用率percentage of passenger seats utilization per car225.客车平均日车公里average car-kilometers per car-day 226.客车洗车线washing siding for passenger vehicle227.客车整备所passenger car servicing depot228.客货运站mixed passenger and freight station229.客流调查passenger flow investigation230.客流量passenger flow volume231.客流图passenger flow diagram232.客票passenger ticket233.空车直达列车through train with empty cars234.空车走行率percentage of empty to loaded car kilometers 235.空间间隔法space-interval method236.空陆水联运集装箱air/surface container237.控温运输transport under controlled temperature 238.跨装straddle239.阔大货物exceptional dimension freight240.劳动定额labor norm241.冷藏运输refrigerated transport242.冷却货物cooled freight243.立柱式托盘post pallet244.连挂速度coupling speed245.连续式调速系统continued type speed control system 246.联轨站junction station247.联络线connecting line248.链斗卸车机unloading machine with chain buckets249.链斗装车机loading machine with chain buckets250.列车保留train stock reserved251.列车编组顺序表train consist list252.列车长train conductor253.列车车次train number254.列车车底需要数number of passenger train set required 255.列车等线train waiting for a receiving track256.列车加开running of extra train257.列车进路train route258.列车客座利用率percentage of passenger seats utilization per train259.列车扣除系数coefficient of train removal260.列车平均载客人数average number of passengers carried per train261.列车平均总重average train gross weight262.列车去向train destination263.列车确报train list information after departure264.列车事故train accident265.列车停运withdrawal of train266.列车预报train list information in advance267.列车员train attendant268.列车运缓train running delay269.列车运行调整train operation adjustment270.列车运行时刻表timetable271.列车运行线train path272.列车运行正点率percentage of punctuality of trains running to tot273.列车重量标准railway train load norm274.临时旅客列车extra passenger train275.零担仓库scattered freight storehouse276.零担货物less-than-carload freight277.零担货物中转站less-than-carload freight transshipment station278.溜车不利条件unfavorable condition for car rolling279.溜车有利条件favorable condition for car rolling280.流动资金周转turnover of current capital281.路网性编组站network marshalling station282.路用列车railway service train283.旅客乘车系数coefficient of passengers traveling by trains284.旅客乘降所passenger stop point285.旅客换乘passenger transference286.旅客快车fast passenger train287.旅客列车包车制responsi bility crew system of passenger train288.旅客列车包乘制assigning crew system of passenger train 289.旅客列车编组passenger train formation290.旅客列车车底周转时间turnaround time of passenger train set291.旅客列车乘务制度crew working system of passenger train 292.旅客列车乘务组passenger train crew293.旅客列车轮乘制crew pooling system of passenger train 294.旅客列车直达速度through speed of passenger train295.旅客人公里成本cost per passenger kilometer296.旅客伤亡passenger casualty297.旅客特别快车express train298.旅客运输计划passenger traffic plan299.旅客运输量volume of passenger traffic300.旅客运送人数number of passengers transported301.旅客站舍passenger building302.旅客直达特别快车through express train303.旅客最高聚集人数maximum number of passengers in peak hours304.难行车hard rolling car305.难行线hard running track306.能力储备系数coefficient of reserved capacity307.平面调车场flat marshalling yard308.平台集装箱platform container309.平托盘flat pallet310.平行进路parallel route311.平行运行图parallel train diagram312.坡度牵出线draw-out track at grade313.普通运价general rate314.企业自备车private car4315.牵出线改编能力resorting capacity of lead track316.牵引车及挂车tractor and trailer317.轻浮货物light and bulk freight318.清算收入clearing revenue319.区段小运转列车district transfer train320.区域性编组站regional marshalling station321.日要车计划daily car requisition plan322.容许运输期限permissive period of transport323.三角形枢纽triangle-type junction terminal324.散装货物bulk freight325.伤亡率casualty rate326.上行方向up direction327.设备故障breakdown of equipment328.湿损事故wet damage accident329.十字形枢纽cross-type junction terminal330.时间间隔法time-interval method331.始发直达列车through train originated from one loading point332.市郊客流suburban passenger flow333.市郊旅客列车suburban passenger train334.事故处理settlement of accident335.事故记录accident record336.事故救援accident rescue337.事故率accident rate338.事故赔偿accident indemnity339.事故信息管理accident information management340.事故隐患accident threat341.事故预测accident forecast342.事故预防prevention of acci dent343.售票处booking office344.枢纽小运转列车junction terminal transfer train345.枢纽直径线diametrical line of junction terminal346.输送能力traffic capacity347.双层托盘double-deck pallet348.双推单溜single rolling on double pushing track349.双推双溜double rolling on double pushing track350.双线运行图train diagram for doubletrack351.双向横列式编组站bidirectional transversal type marshalling station352.双向混合式编组站bi directional combined type marshalling station353.双向纵列式编组站bidirectional longitudinal type marshalling statio354.顺列式枢纽longitudinal arrangement type junction terminal355.特快加快票express extra ticket356.铁路保价运输value insured rail traffic357.铁路保险运输insured rail traffic358.铁路财务railway finance359.铁路的连带责任joint responsibility of railway360.铁路固定资产railway fixed assets361.铁路货物运输规程regulations for railway freight traffic 362.铁路货运组织railway freight traffic organization 363.铁路建设基金railway construction fund364.铁路军事运输railway military service365.铁路客运组织railway passenger traffic organization 366.铁路旅客运输规程regulations for railway passsenger traffic367.铁路年度计划annual railway plan368.铁路行车组织organization of train operation369.铁路行车组织规则rules for organization of train operation 370.铁路运输安全safety of railway traffic371.铁路运输调度railway traffic control372.铁路运输利润railway traffic profit373.铁路运输全员劳动生产labor productivity of railway transport374.铁路运输质量管理quality control of railway transportation375.铁路运输周转基金railway traffic turnover fund376.铁路运营railway operation377.铁路职工数number of railway staff and workers378.铁路重载运输railway heavy haul traffic379.停车器stopping device380.通风运输ventilated transport381.通过进路through route382.通过能力限制区间restriction section of carrying capacity 383.通过式货场through-type freight yard384.通过式客运站through-type passenger station385.通用集装箱general purpose container386.推送调车push-pull shunting387.推送速度pushing speed388.脱钩点separation point389.脱鞋器skate throw-off device390.驼峰调车场hump yard391.驼峰调车场头部hump yard classification throat392.驼峰调车场尾部tail throat of a hump yard393.驼峰高度hump height394.驼峰解体能力break-up capacity of hump395.驼峰连结员室coupers cabin at hump crest396.驼峰溜车方向rolling direction of hump397.驼峰溜放部分rolling section of hump398.驼峰溜放线hump lead399.驼峰推送部分pushing section of hump400.驼峰推送线pushing track of hump401.驼峰迂回线roundabout line of hump402.驼峰纵断面hump profile403.危险货物包装标志labels for packages of dangerous goods 404.问讯处information office405.卧铺票berth ticket406.无调中转车transit car without resorting407.无调中转车停留时间detention time of car in transit without resorting408.无效运输ineffective traffic409.无形损耗intangible wear410.下行方向down direction411.鲜活货物fresh and live freight412.险性事故bad acci dent413.现在车cars on hand414.线路全长total track length415.线路所block post416.线路有效长effective track length417.线束track group418.箱底承载能力floor loading capability419.箱门封条door seal gasket420.箱式托盘box pallet421.响墩信号torpedo422.项目评估project appraisal423.卸车数number o f car unloading5424.行包事故luggage and parcel traffic accident425.行包邮政地道tunnel for luggage and postbag426.行车闭塞法train block system427.行车凭证running token428.行车中断traffic interruption429.行李包裹承运acceptance of luggage and parcels430.行李包裹交付delivery of luggage and parcels431.行李包裹托运consigning of luggage and parcels432.行李房luggage office433.行李票luggage ticket434.学生票student ticket435.旬间装车计划ten day car loading plan436.压钩坡coupler compression grade437.咽喉道岔throat point438.咽喉区长度throat length439.要车计划表car planned requisition list440.一般事故ordinary accident441.一次货物作业平均停留average detention time of local car for loading or442.一批货物consignment443.移交车loaded cars to be delivered at junction stations 444.易冻货物freezable freight445.易腐货物perishable freight446.易燃货物inflammable freight447.易行车easy rolling car448.易行线easy running track449.营业外支出non-operating outlay450.营业站operating station451.游车idle car452.有调中转车transit car with resorting453.有调中转车停留时间detention time of car in transit with resorting454.有形损耗tangible wear455.迂回线round about line456.迂回运输roundabout traffic457.月度货物运输计划monthly freight traffic plan458.越行站overtaking station459.越站乘车overtaking the station460.运输安全管理safety management of traffic461.运输安全监察safety supervision of traffic462.运输安全检查safety inspection of traffic463.运输安全控制系统safety control system of traffic 464.运输安全评估safety evaluation of traffic465.运输安全系统工程safety system engineering of traffic 466.运输包装transport package467.运输成本计划traffic cost plan468.运输工作技术计划plan of technical indices for freight traffic469.运输工作日常计划day-to-day traffic working plan 470.运输收入traffic revenue471.运输收入率rate of traffic revenue472.运输条件traffic condition473.运输限制traffic limitation474.运输支出traffic expenditure475.运行图‘天窗’ ‘sky-light’ in the train diagram476.运行图周期period in the train diagram477.运营吨公里ton-kilometers operated478.运用车serviceable car479.运用车保有量number of serviceable cars held kept480.运用车工作量number of serviceable cars turnaround481.运转车长train guard482.运转室operation office for train receiving-departure483.摘挂调车detaching and attaching of cars484.摘挂列车pick-up and drop train485.站场排水yard drainage486.站调楼yard controllers tower487.站界station limit488.站坪station site489.站前广场station square490.站台票platform ticket491.整备线servicing siding492.整车分卸car load freight unloaded at two or more stations493.整车货物car load freight494.直达运输through traffic495.直通场through yard496.直通客流through passenger flow497.直通旅客列车through passenger train498.直通式货运站through-type freight station499.止轮器wheel skid500.制动能高velocity hump crest of retarder501.制动铁鞋brake shoe502.中间坡intermediate grade503.中行车mi ddle rolling car504.中转车平均停留时间average detention time of car in transit505.重车重心center of gravity for car loaded506.重车重心高center height of gravity for car loaded507.重大事故grave accident508.重质货物heavy freight509.主要编组站main marshalling station510.专业性货运站specialized freight station511.装车调整adjustment of car loading512.装车数number of car loadings513.装卸搬运handling514.装卸定额handling quota515.装卸费率rate of handling charge516.装卸工作单handling sheet517.装卸换算吨converted tons of handling518.装卸机械利用率utilization ratio of machine handling519.装卸机械完好率percentage of machine handling in good condition520.装卸机械作业量handling volume by machine521.装卸自然吨actual tons of handling522.装卸作业机械化handling mechanization523.装卸作业量handling volume524.装卸作业自动化handling automation525.装卸作业组织organization of handling526.追踪列车间隔时间time interval between trains spaced by automatic b527.追踪运行图train diagram for automatic block signals528.准备进路preparation of the route529.自理装卸handling by shipper-self530.综合性货运站general freight station531.综合折旧率composite depreciation rate532.总重吨公里gross ton-kilometers533.纵列式区段站longitudinal type district station534.最易行车easiest rolling car6535.货运统计goods traffic statistics536.客运统计passenger traffic statistics537.铁道运营指标铁路运营指标railway operating index 538.货运量goods traffic volume539.货运密度goods traffic density; density of freight traffic 540.货物平均运输距离货物平均运程average haul of goods; average haul of freight traffic541.货物周转量volume of goods turnaround; turnover of freight traffic542.吨公里ton-kilometer543.客运密度passenger traffic density544.旅客平均运输距离旅客平均运程average journey per passenger545.旅客周转量turnover passenger traffic; turnover of passenger traffic546.人公里man-kilometer547.机车周转时间locomotive turnaround time548.列车质量列车重量;列车质量train weight549.货物列车平均重量average weight of goods train550.列车编成辆数average number of cars per train; number of cars in a train551.货车载质量货车载重量wagon load552.货车载重利用率coefficient of utilization of wagon load 553.中时货车中转时间;中时freight car transfer time 554.货车周转时间wagon turnaround time; car turnaround time 555.列车公里train-kilometer; train k ilometers556.列车正点率列车正点指标;列车正点率indices of punctuality of train557.铁盟国际铁路联盟;铁盟international union of railways 558.铁组铁路合作组织;铁组organization for collaboration of railways559.铁路局railway administration560.列车段train crew district561.车务段train operation depot562.调度所dispatching office; traffic controllers office; dispatchers office563.铁路通车里程railway traffic kilometrage564.客运组织organization of passenger traffic565.客运能力capacity of passenger traffic566.客运管理passenger traffic management567.客运指标passenger traffic index568.客运计划plan of passenger traffic569.客运作业passenger traffic service570.旅客服务passenger service571.行包运输traffic for luggage and parcel572.行李保管luggage storage573.售检票系统ticketing-checking system574.列车预告设备train information forecasting equipment 575.旅客问询设备passenger enquiry equipment576.旅客向导设备passenger guiding equipment577.重载货物运输heavy haul transport578.高速货物运输high-speed freight transport579.集装化运输containerized traffic580.集装箱运输container transport; freight container traffic 581.托盘运输pallet transport; pallet traffic582.零担货物运输less-than carload goods transportation 583.整车货物运输car-load traffic584.成件包装货物运输packaged goods transport585.直达货物运输through goods traffic586.门到门运输door-to-door traffic587.驮背运输piggyback transport588.大宗货物运输mass goods transport589.散装货物运输bulk goods transport590.矿石运输mineral transport591.煤炭运输coal transport592.粉状货物运输powder cargo traffic593.石油运输petroleum transport594.油囊运输rubber pouch transport595.罐装货物运输tank freight transport596.液体货物运输liquid freight transport597.长大货物运输long heavy cargo transport598.超限货物运输transport of out-of-gauge good599.笨重货物运输heavy goods transport600.集重货物运输concentrated weight freight traffic601.轻浮货物运输light and bulky goods transport602.专用线运输special line transport603.特种货物运输special goods traffic604.危险货物运输dangerous goods transport605.放射性货物运输transport of radioactive goods606.易燃货物运输inflammable goods traffic607.鲜活货物运输fresh and live goods traffic608.冷藏货物运输refrigerated goods transport609.垃圾运输wastes transportation610.路用运输railway work transport611.保价运输insured price traffic612.货运管理freight traffic management613.货运指标freight index614.货运计划plan of goods transport615.货运作业goods traffic service616.货运计价freight rate calculation617.货运单据goods consignment note618.货物托运goods consignation; consigning of freight619.货物发送originating goods620.货物中转作业transshipment operation of goods621.货物保管custody of goods622.货物交付delivery of goods; delivery of freight623.货运预报goods traffic advance information624.货场管理yard management625.搬运carrying626.包装packaging627.装卸作业loading and unloading operation628.装卸能力handling capacity629.装车loading630.卸车unloading631.保鲜技术technique of fresh preservation of goods632.冷藏refrigerate633.制冷技术technique of refrigeration634.制冷剂refrigerant635.装卸技术loading technique636.装卸机械化loading and unloading mechanization637.装载loading638.装载限界loading clearance; loading clearance limit; loading gauge639.满载full load640.超载enhanced loading641.偏载unbalanced loading642.重车稳定性stability of loaded wagon643.电瓶车battery truck; storage battery car7。

Horizontal and Vertical Alignment水平和竖直定位1 Background1背景One definition of a visually attractive and unobtrusive highway is the degree to which the horizontal and vertical alignments of the route have been integrated into its surrounding natural and human environments. This takes careful planning and design, as noted in the AASHTO Green Book: Coordination of horizontal alignment and profile should not be left to chance but should begin with preliminary design, during which adjustments can readily be made ... The designer should-study long, continuous stretches of highway in both plan and profile and visualize the whole in three dimensions.一条引人注目的公路和一条不引人注目的公路的区别在于这条公路的水平和竖直定位融入到周围自然和人文环境的程度。

这需要认真的规划和设计，就像AASHTO Green一书中提到的：“水平面的位置和分布的协调不应该由机遇决定，而应该是由很容易做调整的初步设计决定……”设计者应进行长时间的研究，并具有把整个不断延伸的公路的平面和剖面三维化的能力。

外文文献翻译原文：Asphalt Mixtures-Applications, Theory and Principles1 . ApplicationsAsphalt materials find wide usage in the construction industry. The use of asphalt as a cementing agent in pavements is the most common of its applications, however, and the one that will be consid ered here.Asphalt products are used to produce flexibl e pavements for highways and airports. The term “fl exible” is used to distinguish these pavements from those made with Portland cement, which are classified as rigid pavements, that is, having beam strength. This distinction is important because it provid es they key to the design approach which must be used for successful flexibl e pavement structures.The flexibl e pavement classification may be further broken d own into high and l ow types, the type usually depending on whether a solid or liquid asphalt product is used. The l ow types of pavement are mad e with the cutback, or emulsion, liquid products and are very widely used throughout this country. Descriptive terminology has been devel oped in various sections of the country to the extent that one pavement type may have several names. However, the general process foll owed in construction is similar for most l ow-type pavements and can be described as one in which the aggregate and the asphalt product are usually applied to the roadbed separately and there mixed or all owed to mix, forming the pavement.The high type of asphalt pavements is made with asphalt cements of some sel ected penetration grad e.Fig. ·1 A modern asphalt concrete highway. Should er striping is used as a safely feature.Fig. ·2 Asphalt concrete at the San Francisco International Airport.They are used when high wheel l oads and high volumes of traffic occur and are, therefore, often designed for a particular installation.2 . Theory of asphalt concrete mix designHigh types of flexible pavement are constructed by combining an asphalt cement, often in the penetration grad e of 85 to 100, with aggregates that are usually divided into three groups, based on size. The three groups are coarse aggregates, fine aggregates, and mineral filler. These will be discussed in d etail in later chapter.Each of the constituent parts mentioned has a particular function in the asphalt mixture, and mix proportioning or d esign is the process of ensuring that no function is negl ected. Before these individual functions are examined, however, the criteria for pavement success and failure should be consid ered so that d esign objectives can be established.A successful fl exible pavement must have several particular properties. First, it must be stable, that is to resistant to permanent displacement under l oad. Deformation of an asphalt pavement can occur in three ways, two unsatisfactory and one desirable. Plastic d eformationof a pavement failure and which is to be avoid ed if possible. Compressive deformation of the pavement results in a dimensional change in the pavement, and with this change come a l oss of resiliency and usually a d egree of roughness. This deformation is less serious than the one just described, but it, too, leads to pavement failure. The desirabl e type of deformation is an elastic one, which actually is beneficial to flexibl e pavements and is necessary to their long life.The pavement should be durable and should offer protection to the subgrade. Asphalt cement is not impervious to the effects of weathering, and so the design must minimize weather susceptibility. A durable pavement that does not crack or ravel will probably also protect the roadbed. It must be remembered that fl exible pavements transmit l oads to the subgrad e without significant bridging action, and so a dry firm base is absolutely essential.Rapidly moving vehicl es d epend on the tire-pavement friction factor for control and safety. The texture of the pavement surfaces must be such that an adequate skid resistance is developed or unsafe conditions result. The design procedure should be used to sel ect the asphalt material and aggregates combination which provid es a skid resistant roadway.Design procedures which yield paving mixtures embodying all these properties are not available. Sound pavements are constructed where materials and methods are selected by using time-tested tests and specifications and engineering judgments al ong with a so-call ed design method.The final requirement for any pavement is one of economy. Economy, again, cannot be measured directly, since true economy only begins with construction cost and is not fully determinable until the full useful life of the pavement has been record ed. If, however, the requirements for a stable, durable, and safe pavement are met with a reasonable safety factor, then the best interests of economy have probably been served as well.With these requirements in mind, the functions of the constituent parts can be examined with consideration give to how each part contributes to now-established objectives or requirements. The functions of the aggregates is to carry the l oad imposed on the pavement, and this is accomplished by frictional resistance and interl ocking between the individual pieces of aggregates. The carrying capacity of the asphalt pavement is, then, related to the surface texture (particularly that of the fine aggregate) and the density, or “compactness,”, of the aggregates. Surface texture varies with different aggregates, and while a rough surfacetexture is desired, this may not be available in some l ocalities. Dense mixtures are obtained by using aggregates that are either naturally or artificially “well grad ed”. This means that the fine aggregate serves to fill the voids in the coarser aggregates. In addition to affecting density and therefore strength characteristics, the grading also influences workability. When an excess of coarse aggregate is used, the mix becomes harsh and hard to work. When an excess of mineral filler is used, the mixes become gummy and difficult to manage.The asphalt cement in the fl exibl e pavement is used to bind the aggregate particl es together and to waterproof the pavements. Obtaining the proper asphalt content is extremely important and bears a significant influence on all the items marking a successful pavement. A chief objective of all the design methods which have been devel oped is to arrive at the best asphalt content for a particular combination of aggregates.3 . Mix design principl esCertain fundamental principles underlie the design procedures that have been developed. Before these procedures can be properly studied or applied, some consid eration of these principles is necessary.Asphalt pavements are composed of aggregates, asphalt cement, and voids. Consid ering the aggregate alone, all the space between particles is void space. The volume of aggregate voids depends on grading and can vary widely. When the asphalt cement is ad ded, a portion of these aggregate voids is fill ed and a final air-void volume is retained. The retention of thisair-void volume is very important to the characteristics of the mixture. The term air-void volume is used, since these voids are weightless and are usually expressed as a percentage of the total volume of the compacted mixture.An asphalt pavement carries the applied load by particl e friction and interlock. If the particl es are pushed apart for any reason , then the pavement stability is d estroyed. This factor indicates that certainly no more asphalt shoul d be ad ded than the aggregate voids can readily hold. However ,asphalt cement is susceptible to volume change and the pavement is subject to further compaction under use. If the pavement has no air voids when placed, or if it loses them under traffic, then the expanding asphalt will overfl ow in a condition known as bleeding. The l oss of asphalt cement through bl eeding weakens the pavement and also reduces surface friction, making the roadway hazard ous.Fig. ·3 Cross section of an asphalt concrete pavement showing the aggregate framework bound together by asphalt cement.The need for a minimum air-void volume (usually 2 or 3 per cent ) has been established. In addition, a maximum air-void volume of 5 to 7 per cent shoul d not be exceed. An excess of air voids promotes raveling of the pavement and also permits water to enter and speed up the deteriorating processes. Also, in the presence of excess air the asphalt cement hard ens and ages with an accompanying loss of durability and resiliency.The air-void volume of the mix is determined by the d egree of compaction as well as by the asphalt content. For a given asphalt content, a lightly compacted mix will have a large voids volume and a l ower d ensity and a greater strength will result. In the laboratory, the compaction is controlled by using a specified hammer and regulating the number of bl ows and the energy per blow. In the fiel d, the compaction and the air voids are more difficult to control and tests must be made no specimens taken from the compacted pavement to cheek on the d egree of compaction being obtained. Traffic further compact the pavement, andall owance must be mad e for this in the design. A systematic checking of the pavement over an extend ed period is needed to given factual information for a particular mix. A change in density of several per cent is not unusual, however.Asphalt content has been discussed in connection with various facets of the ix design problem. It is a very important factor in the mix design and has a bearing an all the characteristics ld a successful pavement: stability, skid resistance, durability, and economy. As has been mentioned, the various design procedures are intended to provid e a means for selecting the asphalt content . These tests will be consid ered in detail in a future chapter ,butthe relationship between asphalt content and the measurable properties of stability, unit weight, and air voids will be discussed here.Fig.4 Variations in stability, unit weight, and air-void content with asphalt cement content.If the gradation and type of aggregate, the degree of compaction, and the type of asphalt cement are controll ed, then the strength varies in a predictable manner. The strength will increase up to some optimum asphalt content and then decrease with further additions. The pattern of strength variation will be different when the other mix factors are changed, and so only a typical pattern can be predicted prior to actual testing.Unit weight varies in the same manner as strength when all other variabl e are controll ed. It will reach some peak value at an asphalt content near that determined from the strength curve and then fall off with further additions.As already mentioned, the air-void volume will vary with asphalt content. However, the manner of variation is different in that increased asphalt content will d ecrease air-void volume to some minimum value which is approached asymptotically. With still greater additions of asphalt material the particles of aggregate are only pushed apart and no change occurs in air-void volume.In summary, certain principles involving aggregate gradation, air-void volume, asphalt content, and compaction mist be understood before proceeding to actual mix d esign. The proper design based on these principl es will result in sound pavements. If these principles are overl ooked, the pavement may fail by one or more of the recognized modes of failure: shoving, rutting, corrugating, becoming slick when the max is too ‘rich’; raveling, cracking, having low durability whe n the mix is too ‘l ean’.It should be again emphasized that the strength of flexible is, more accurately, a stabilityand d oes not indicate any ability to bridge weak points in the subgrade by beam strength. No asphalt mixture can be successful unless it rests on top of a properly designed and constructed base structure. This fact, that the surface is no better than the base, must be continually in the minds of those concerned with any aspect of fl exible pavement work.译文：沥青混合料的应用、理论和原则1、应用沥青材料如今在建筑行业广泛使用。

公路建设外文翻译文献(文档含中英文对照即英文原文和中文翻译)PavementHighway pavements are divided into two main categories: rigitand flexible.The wearing surfaceof a rigid pavement is usually constructed of Portland cement concrete such that it acts like a beam over any irregularities in the underlying supporting material.The wearing surface of flexible pavements, on the other hand, is usually constructed of bituminous material such that they remain in contact with the underlying material even when minor irregularities occur.Flexible pavements usually consist of a bituminous surface underlaid with a layer of granular material and a layer of a suitable mixture of coarse and fine materials.Coarse aggregatesFine aggregatesTraffic loads are transferred by the wearing surface to the underlying supporting materials through the interlocking of aggregates, the frictionaleffect of the granular materials, and the cohesion of the fine materials.Flexible pavements are further divided into three subgroups: high type, intermediate type, and low type. High-type pavements have wearing surfaces that adequately support the expected traffic load without visible distress due to fatigue and are not susceptible to weather conditions.Intermediate-type pavements have wearing surfaces that range from surface treated to those with qualities just below that of high-type pavements. Low-type pavements are used mainly for low-cost roads and have wearing surfaces that range from untreated to loose natural materials to surface-treated earth.✹The components of a flexible pavement include the subgradeor prepared roadbed, the subbase, basecourse, and the surface course (Fig.11.1).✹Upper surface courseMiddle surface courseLower surface courseThe performance of the pavement depends on the satisfactory performance of each component, which requires proper evaluation of the properties of each component separately.✹The subgrade is usually the natural material located along the horizontal alignment of the pavement and serves as the foundation of the pavement structure.✹The subgrademay also consist of a layer of selected borrow materials, well compacted to prescribedspecifications.✹Compacting plantCompaction deviceCompactnessIt may be necessary to treat the subgrade material to achieve certain strength properties required for the type of pavement being constructed.Located immediately above the subgrade, the subbase component consists of a superior quality to that which generally is used for subgrade construction. The requirements for subbase materials are usually given in terms of the gradation, plastic characteristics, and strength. When the quality of the subgrade material meets the requirements of the subbase material, the subbase component may be omitted.In cases where suitable subbase material is not readily available ,the available material can be treated with other materials to achieve the necessary properties. This process of treating soils to improve their engineering properties is know as stabilization.✹The base course lies immediately above the subbase. It is placed immediately above the subgrade if a subbase course is not used.✹This course usually consists of granular materials such as crushed stone, crushed or uncrushed.The specifications for base course materials usually include stricter requirements than those for subbase materials, particularly with respect to their plasticity, gradation, and strength.Materials that do not have the required properties can be used as base materials if they are properly stabilized with Portland cement, asphalt, or lime .In some cases, high-quality base course materials may also be treated with asphalt or Portland cement to improve the stiffness characteristics of heavy-duty pavementsThe surface course is the upper course of the road pavement and is constructed immediately above the base course. The surface course in flexible pavement usually consists of a mixture of mineral aggregates and asphaltic materials.It should be capable of withstanding high tire pressures, resisting the abrasive forces due to traffic, providing a skid-resistant driving surface, and preventing the penetration of surface water into the underlying layers.✹The thickness of the wearing surface can vary from 3 in. to more than 6 in.（inch，英寸，2.54cm）, depending on the expected traffic on the pavement.It was shown that the quality of the surface course of a flexible pavement depends on the mix design of the asphalt concrete used.✹Rigid highway pavements usually are constructed to carry heavy traffic loads, although they have been used for residential and local roads. Properly designed and constructed rigid pavements have long service lives and usually are less expensive to maintain than the flexible pavements.✹The Portland cement concrete commonly used for rigid pavements consists of Portland cement, coarse aggregate, fine aggregate, and water. Steel reinforcing rods may or may not be used, depending on the type of pavement being constructed.Rigid highway pavements be divided into three general type: plain concrete pavements, simply reinforced concrete pavements, and continuously reinforced concrete pavement. The definition of each pavement type is related to the amount of reinforcement used.Plain concrete pavement has no temperature steel or dowels for load transfer.However, steel tie bars are often used to provide a hingeeffect at longitudinal joints and to prevent the opening of these joints. Plain concrete pavements are used mainly on low-volume highways or when cement-stabilized soils are used as subbase.Joints are placed at relatively shorter distances (10 to 20 ft) than with the other types of concrete pavements to reduce the amount of cracking.In some case, the transverse joints of plain concrete pavements are skewed about 4 to 5 ft in plan, such that only one wheel of a vehicle passes through the joint at a time. This helps to provide a smoother ride.Simply reinforced concrete pavements have dowels for the transfer of traffic loads across joints, with these joints spaced at larger distances, ranging from 30 to 100 ft. Temperature steel is used throughout the slab, with the amount dependent on the length of the slab. Tie bars are also commonly used in longitudinal joints.Continuously reinforced concrete pavements have no transverse joints, except construction joints or expansion joints when they are necessary at specific positions, such as at bridges.These pavements have a relatively high percentage of steel, with the minimum usually at 0.6 percent of the cross section of the slab. They also contain tie bars across the longitudinal joints.h/2h/25~10cm填缝料 横向施工缝构造填缝料平缝加拉杆型Bituminous Surface CoursesThe bituminous surface course has to provide resistance to the effects of repeated loading by tyres and to the effects of the environment.✹In addition, it must offer adequate skid resistance in wet weather as well as comfortable vehicle ride. It must also be resistant to rutting and to cracking.✹It is also desirable that surface course is impermeable, except in the case of porous asphalt.Hot rolled asphalt (HRA) is a gapgraded material with less coarse aggregate. In fact it is essentially a bitumen/fine aggregate/filler mortar into which some coarse aggregate is placed.The mechanical propertiesare dominated by those of the mortar. This material has been extensively used as the wearing course on major road in the UK, though its use has recently declined as new materials have been introduced.✹It provides a durablelayer with good resistance to cracking and one which is relatively easy to compact. The coarse aggregate content is low (typically 30%) which results in the compacted mixture having a smooth surface. Accordingly, the skid resistance is inadequate and precoated chippings are rolled into the surface at the time of laying to correct this deficiency.In Scotland, HRA wearing course remains the preferred wearing course on trunk roads including motorway but，since 1999 thin surfacings have been the preferred option in England and Wales. Since 1999 in Northern Ireland, HRA wearing course and thin surfacings are the preferred permitted options.Porous asphalt (PA) is a uniformly graded material which is designed to provide large air voids so that water can drain to the verges within the layer thickness. If the wearing course is to be effective, the basecourse below must be waterproof and the PA must have the ability to retain its open textured properties with time.Thick binder films are required to resist water damage and ageing of the binder. In use, this material minimizes vehicle spray, provides a quiet ride and lower rolling resistance to traffic than dense mixtures.✹It is often specified for environmental reasons but stone mastic asphalt (SMA) and special thin surfacings are generally favoured in current UK practice.There have been high profile instances where a PA wearing course has failed early in its life. The Highways Agency does not recommend the use of a PA at traffic levels above 6000 commercial vehicles per day.✹Asphaltic concrete and dense bitumen macadam (DBM) are continuously graded mixtures similar in principle to the DBMs used in roadbases and basecourses but with smaller maximum particle sizes. Asphaltic concrete tends to have a slightlydenser grading and is used for road surfaces throughout the world with the excepting of the UK.✹It is more difficult to meet UK skid resistance Standards with DBMs than HRA, SMA or PA. This problem can be resolves by providing a separate surface treatment but doing so generally makes DBM economically unattractive.✹Stone mastic asphalt (SMA) material was pioneeredin Germany and Scandinavia and is now widely used in the UK. SMA has a coarse, aggregrate skeleton, like PA, but the voids are filled with a fine aggregate/filler /bitumen mortar.✹In mixtures using penetration grade bitumen , fibres are added to hold the bitumen within the mixture (to prevent “binder drainage”).Bitumen✹oil bitumen( earth oil)✹natural bitumen✹TarWhere a polymer modified bitumen is used, there is generally no need for fibres. SMA is a gap-graded material with good resistance to rutting and high durability. modified bitumen✹SBS✹SBR✹PE\EV A✹It differs from HRA in that the mortar is designed to just fill the voids in the coarse aggregate whereas, in HRA, coarse aggregate is introduced into the mortar and does not provide a continous stone matrix. The higher stone content HRAs ,however, are rather similar to SMA but are not wide used as wearing courses in the UK, being preferred for roadbase and basecourse construction.A variety of thin and what were called ultra thin surfacings (nowadays, the tendency is to use the term …thin surfacings‟ for both thin and ultra thin surfac ings ) have been introduced in recent years, principally as a result of development work concentrated in France.These materials vary in their detailed constituents but usually have an aggregate grading similar to SMA and often incorporate a polymer modified bitumen.They may be used over a high stiffness roadbase and basecourse or used for resurfacing of existing pavements. For heavy duty pavements (i .e those designed to have a useful life of forty years), the maintenance philosophy is one of minimum lane occupancy, which only allows time for replacement of the wearing course to these …long life‟ pavement structures. The new generation of thin surfacings allows this to be conveniently achieved.The various generic mixture types described above can be compared with respect to their mechanical properties and durability characteristics by reference to Fig.12.1. This shows, in principle, how low stone content HRA, asphaltic concrete, SMA and PA mixtures mobilize resistance to loading by traffic.Asphaltic concrete (Fig.12.1a)) presents something of a compromise when well designed, since the dense aggregate grading can offer good resistance to the shear stresses which cause rutting, while an adequate binder content will provide reasonable resistance to the tensile stresses which cause cracking.In general, the role of the aggregate dominates. DBMs tend to have less dense gradings and properties which, therefore, tend towards good rutting resistance andaway from good crack resistance.HRA (Fig.12.1b)) offers particularly good resistance to cracking through the binder rich mortar between the coarse aggregate particles. This also provides good durability but the lack of coarse aggregate content inhibits resistance to rutting.SMA and PA are shown in the same diagram ( Fig.c)) to emphasis the dominant role the coarse aggregate. In both case, well coated stone is used. In PA, the void space remains available for drainage of water, whilst in SMA, the space is occupied by a fine aggregate/ filler/ bitumen/ fibre mortar.Both materials offer good rutting resistance through the coarse aggregate content. The tensile strength of PA is low whilst that of SMA is probably adequate but little mechanical testing data have been reported to date.Drainage for Road and Airports✹Provision of adequate drainage is important factor in the location and geometric design of road and airports. Drainage facilities on any highway, street and airport should adequately provide for the flow of water away from the surface of the pavement to properly designed channels.Inadequate drainage will eventually result in serious damage to the structure.✹In addition, traffic may be slowed by accumulated water on the pavement, and accidents may occur as a result of hydroplaning and loss of visibility from splash and spray. The importance of adequate drainage is recognized in the amount of highway construction dollars allocated to drainage facilities. About25 percent of highway construction dollars are spent for erosion control anddrainage structures, such as culverts, bridges, channels, and ditches.✹Highway Drainage Structures✹One of the main concerns of the highway engineer is to provide an adequate size structure, such that the waterway opening is sufficiently large to discharge the expected flow of water.Inadequately sized structures can result in water impounding, which may lead to failure of the adjacent sections of the highway due to embankments being submerged in water for long periods.✹The two general categories of drainage structures are major and minor. Major structures are those with clear spans greater than 20 feet, whereas minor structures are those with clear spans of 20 feet or less .✹Major structures are usually large bridges, although multiple-span culverts may also be included in this class. Minor structures include small bridges and culverts.Emphasis is placed on selecting the span and vertical clearancerequirements for major structures. The bridge deck should be located above the high water mark .The clearance above the high water mark depends on whether the waterway is navigable ✹If the waterway is navigable, the clearance above the high water mark should allow the largest ship using the channel to pass underneath the bridge without colliding with the bridge deck. The clearance height, type, and spacing of piers also depend on the probability of ice jams and the extentto which floating logs and debris appear on the waterway during high water.✹An examination of the banks on either side of the waterway will indicate the location of the high water mark, since this is usually associated with signs of erosion and debris deposits. Local residents, who have lived near and observed the waterway during flood stages over a number of years, can also give reliable information on the location of the high water mark. Stream gauges that have been installed in the waterway for many years can also provide data that can be used to locate the high water mark.Minor structures, consisting of short-span bridges and culverts, are the predominant type of drainage structures on highways. Although openings for these structures are not designed to be adequate for the worst flood conditions, they shouldbe large enough to accommodate the flow conditions that might occur during the normal life expectancy of the structure.✹Provision should also be made for preventing clogging of the structure due to floating debris and large boulders rolling from the banks of steep channels.✹Culverts are made of different materials and in different shapes. Materials used to construct culverts include concrete（reinforced and unreinforced）, corrugated steel, and corrugatedaluminum. Other materials may also be used to line the interiorof the culvert to prevent corrosion and abrasionor to reduce hydraulic resistance. For example, asphaltic concrete may be used to line corrugated metal culverts. The different shapes normally used in culvert construction include circular, rectangular (box), elliptical, pipe arch, metal box, and arch.✹The drainage problem is increased in these areas primarily for two reasons: the impervious nature of the area creates a very high runoff; and there is little room for natural water courses. It is often necessary to collect the entire storm water into a system of pipes and transmit it over considerable distances before it can be loosed again as surface runoff. This collection and transmission further increase the problem, since all of the water must be collected with virtually no pending, thus eliminating any natural storage; and through increased velocity the peak runoffs are reached more quickly.Also, the shorter times of peaks cause the system to be more sensitive to short-duration,high intensive rainfall.Storm sewers,like culverts and bridges,are designed for storms of various intensity-return-period relationships, depending upon the economy and amount of ponding that can be tolerated.✹Airport Drainage✹The problem of providing proper drainage facilities for airports is similar in many ways to that of highways and streets. However, because of the large and relatively flat surface involved, the varying soil conditions, the absence of natural water courses and possible side ditches, and the greater concentration of discharge at the terminus of the construction area, some phases of the problem are more complex. For the average airport the over-all area to be drained is relatively large and an extensive drainage system is required. The magnitude of such a system makes it even more imperative that sound engineering principles based on all of the best available data be used to ensure the most economical design.Overdesigning of facilities results in excessive money investment with no return, and underdesigning can result in conditions hazardous to the air traffic using the airport. In order to ensure surfaces that are smooth, firm, stable, and reasonably free from flooding, it is necessary to provide a system which will do several things.It must collect and remove the surface water from the airport surfaces; intercept and remove surface water flowing toward the airport from adjacent areas; collect and remove any excessive subsurface water beneath the surface of the airport facilities and in many cases lower the ground-water table; and provide protection against erosion of the sloping areas.路面公路的路面被分为两类：刚性的和柔性的。