●一Unit 1 Highway Introduction
● 1. History
The first road builders of any significance in western Europe were the Romans, to whom the ability to move quickly from one part of the Europe to another was important for military and civil reasons. Roman roads are characterized by their linearity and, in popular perception, by their durability. A good alignment was sought since this provides the most direct route and since the risk of ambush in hostile territory is reduced. It was for this reason that the surface of the road was often elevated a meter or more above the local ground level – to provide a clear view of the surrounding country; hence the modern term “highway”. The durability of such pavement is less absolute but nevertheless well exceeds anything achieved for many centuries after the fall of the Empire.
During the Dark Ages – and indeed well after that – no serious attempt was made in the UK to either maintain or replace the Roman road network, which consequently deteriorated. By the end of the Middle Ages there was in practice no road system in the country. Such routes as existed were unpaved tracks, swampy and impassable for most of the year and dusty and impassable for the remainder. Diversions around particularly poor lengths of road, private land or difficult topography had resulted in sinuous alignments. The general lawlessness combined with these characteristics to discourage all but the most determined travelers.
The first small change in this state of affairs was brought about by an Act of 1555 which imposed a duty on each parish to maintain its roads and to provide a Surveyor of Highways. As this post was unpaid and under-resourced, and as the technical skills did not exist to match the task in hand, the obvious expectation that the post of Surveyor was unpopular and ineffective is generally correct.
● 2. Aim of highway engineering
Roads provide a key element of the infrastructure whoes function is to promote economic activity and improve the standard of living of the population. Highway engineering is concerned with the best use of resources to ensure that a suitable network is provided to satisfy this need of an economically sophisticated society.
Originally roads were little more than tracks across the countryside and were hard, dry and dusty in summer and sodden and impassable in winter. The practice arose, initially in towns, of paving the surface of the road with resilient naturally occurring materials such as stone flags, and such a surface became known as a pavement. Today this term is applied to any surface intended for traffic and where the native soil has been protected from the harmful effects of that traffic by providing an overlay of imported or treated material. The purpose of providing this protection is to enable traffic to move more easily – and therefore more cheaply or quickly – along the road.
● 3. Highway types
A freeway, as defined by statute, is a highway in respect to which the owners of abutting lands have no right or easement of access to or from their abutting lands or in respect to which such owners have only limited or restricted right or easement of access. This statutory definition also includes expressway. The engineering definitions for use in this
manual are:
Unit 4 Asphalt and Mix Asphalt
● 1. Asphalt defined
Although there are natural deposits of asphalt, or rock asphalt, most used today is produced during the refining of crude oil. Asphalt is a constituent of most petroleums and is isolated through the refining process
One of the characteristics and advantages of asphalt as an engineering construction and maintenance material is its versatility. Although a semi-solid at ordinary temperatures, asphalt may be liquefied by applying heat, dissolving it in solvents, or emulsifying it. …….
The largest use of asphalt binder is for HMA. After compacting and cooling to air temperature, HMA is a very strong paving material with the ability to sustain heavy traffic loads while remaining flexible enough to withstand ambient environmental conditions and stress. Over 96 percent of the hard-surfaced roads in the United States are paved using HMA.
● 1.2 Emulsified Asphalt
Emulsified asphalts (also known as emulsions) are low-viscosity mixtures of tiny asphalt binder droplets, water and emulsifying agents. The emulsifying agent coats the surfaces of the asphalt droplets and keeps them suspended in the water prior to application. …
● 1.2 Emulsified Asphalt
… After application, the asphalt emulsion breaks and the water separates and evaporates. Emulsions are brownish in color during application, but after breaking, the asphalt binder returns to its original black color. Emulsions are used for a Tack Coat between subsequent layers of HMA to aid in binding the layers together.
● 3. Hot-mix asphalt
The paving or finishing machine places the HMA at temperatures between approximately 225 and 300 degree of Fahrenheit, depending on the mixture characteristics, layer thickness and ambient conditions. ……
● 4. The activity to modify asphalt properties
Pitch, when added to asphalt, has the effect of increasing the rate at which the binder oxidizes on exposure to the atmosphere. One of the effects of oxidation is that the binder loses flexibility and therefore becomes harder and more susceptible to the abrasive effects of traffic; an oxidized binder is thus likely to wear away in preference to particles of coarse aggregate set in the surface, allowing the chipping to protrude from the surface and improve the skidding resistance. …
Unit 5 Cement and Concrete
● 1. Cement
The main property of cement is that it is capable of acting as a binder forming a rigid matrix in which particles of aggregate may be set. …
● 1. Cement
… Cement is produced from calciferous material, such as chalk or limestone, and
materials such as clay which are rich in silica and alumina. These are reduced to powder form by milling, mixed in the appropriate proportions and heated to such a temperature that the material sinters, forming a coarse clinker which when cooled and ground is the basic ingredient of ordinary Portland cement (OPC).
This material is a mixture of calcium aluminate and calcium silicate, both of which react with water to form the familiar stone-like mass. It was the resemblance of this hydrated material to Portland stone, a high-quality limestone, which gave the material its generic name. Since the cement reacts with water, it is important to ensure that sufficient water is present at the required time to enable the reaction to continue to completion, and that this water remains present whil e it is needed. …
If the mix is allowed to dry out while curing is taking place, weakness will result. If on the other hand too much water is allowed into the mix then the strength of the hydrated cement mass will again be impaired because the excess water will not be used up in the reaction and will remain to form voids in the hardened material – thus reducing its strength.
● 3. Reinforced concrete
It is generally known that concrete is weak in tension, with a tensile strength averages only about 1/10 of the compressive strength. Therefore steel reinforcing bars are embedded in concrete structures where tensile stress may occur to take up the tension after the concrete has cracked. …
● 3. Reinforced concrete
… Without this reinforcement, the good compress ive strength of concrete cannot be fully put into action. Generally speaking, reinforced concrete structures possess the following features: …
Unit 6 Measuring Technology and Equipment
1. Distance measurement
One of the fundamentals of surveying is the need to measure distance. Distances are not necessarily linear, especially if they occur on the spherical earth. In this subject we will deal with distances in Euclidean space, which we can consider a straight line from one point or feature to another. Distance between two points can be horizontal, slope, or vertical. …
1. Distance measurement
… Horizontal and slope distances can be measured with lots of techniques of measurement depending on the desired quality of the result. In plane surveying, the distance between two points means the horizontal distance. If the points are at different elevations, then the distance is the horizontal length between plumb lines at the points. Here gives a brief summary of relevant techniques and their respective accuracies.
2. Angle and direction measurement
Horizontal and vertical angles are fundamental measurements in surveying. It is necessary to be familiar with the meanings of certain basic terms before describing angle and direction measurement. The terms discussed here have reference to the actual figure of the earth.
Unit 8 The Subgrade Design and Construction Technology
The subgrade is comprised of the uppermost materials placed in the road bed embankment or the soil remaining at the base of a cut. The subgrade soil is often referred to
as the foundation or road bed soil. This foundation component is usually constructed of native inorganic soil often in combination with imported soils from select borrow sources, and would be compacted to a specified density and moisture content.
● 1. Soil classification
The basic components of soils are differentiated on the basis of grain size as follows:
● 2. Subgrade strength evaluation
The characteristic material property of subgrade soils used for pavement design is the resillient modulus (MR). The resillient modulus is defined as being a measure of the elastic property of a soil recognizing selected non-linear characteristics. …
● 2. Subgrade strength evaluation
… Methods for the determination of MR are des cribed in AASHTO T294.92 test method. For many years, standard California Bearing Ratio tests were utilized to measure the subgrade strength parameter as a design input.
3. Seasonal variations
One of the most critical conditions that developes in a seasonal frost area such as Alberta is the weakening of the subgrade during the spring thaw period. This weakening results from the melting of ice segregation within the subgrade soils and, to a lesser extent, due to higher moisture contents during this period associated with reduced drainage.
● 4. Swelling soil potential
Excessively expansive soils such as highly plastic clays or bentonitic shales require special attention particularly when in close proximity to the surface of the road embankment. These materials contain minerals which result in volume changes (swelling and shrinking) with changes in moisture content.
● 5. Frost susceptibility
Although some volumetric expansion occurs due to the freezing, a more significant issue relates to the spring melt period. The thaw will release excess water which causes a loss of subgrade strength and potential damage to the roadway pavement structure if the structure has not been designed to account for weakened subgrade support.
Unit 9 Pavement Design and Construction Technology
● 1. Nature of a pavement
The highway engineer is concerned with the provision of a safe, stable and durable surface over which traffic may move. A modern pavement consists of a number of elements. These have various functions which contribute to the ability of the pavement to remain safe, stable and durable for a period of time and under the action of weather and of large numbers of vehicles.
● 2. Mode of failure
Taking a very broad view, there are two types of pavement failure. Failure of the surfacing may take the form of loss of surface texture, loss of surface regularity or loss of impermeability. In the assurance that such failure is not deep-seated, remedial measures will consist of repairs to or replacement of the surfacing only. Such failure can often be prevented or greatly postponed by a careful choice of surfacing materials.
● 3. Cause of failure
Only in the most extraordinary circumstances is it the case that a new pavement is caused to fail by the application of a single wheel load, of whatever magnitude. The general experience is that repeated applications of loads result in the repeated development of stresses tending to cause failure, and that the ability to withstand strain progressively diminishes with the increasing number of load applications. When failure occurs, it is as a result of material fatigue. This concept is the basis of current design practice.
● 4. Pavement life
In a few cases the required life of a pavement is determined by external circumstances; for example, a temporary road to serve a major construction site might be designed to last for the duration of the construction works and no more. Generally however the matter is less clear-cut.
Unit 10 Highway Alignment Design
A facility’s horizontal and ve rtical alignments establish the general character of a roadway, perhaps more than any other design consideration. The configuration of line and grades affects safe operating speeds, sight distances, opportunities for passing, and highway capacity. Decisions on alignment have a significant impact on construction costs, and social and environmental issues. …
Alignment is defined by several factors, including: the length of tangent sections, the transition into horizontal curves, the degree of curvature (radii) for horizontal curves, the transition out of the curves, the rate of superelevation applied to the horizontal curves, and the rate of grade change for any vertical curves.
● 1. Horizontal alignment
Horizontal alignment of a roadway is defined graphically using a series of straight-line tangents with transition sections into and out of horizontal curves. Many factors, including terrain conditions, physical features and right-of-way considerations, affect the design of tangent and curve sections.
● 2 General criteria
Design speed is the principal factor controlling horizontal alignment design. Several geometric standards related to design speed are very specific. Other criteria cannot be defined as specifically and require that judgements be made in consideration of local conditions. The following guidelines outline some of these decisions.
● 3. Sight distance on horizontal curves
An important element in ensuring driver safety and maintaining a roadway’s operational efficiency is providing adequate sight distance - the length of roadway ahead visible to the driver. Sight distance applies to four conditions that arise when setting a project’s horizontal alignment: …
Unit 14 Bridge Introduction
A bridge is a structure providing passage over an obstacle such as a valley, road, railway, canal, river, without closing the way beneath. The required passage may be for road, railway, canal, pipeline, cycle track or pedestrians.
● 1. Components of a bridge
Figure 14-1a) shows the elevation while Fig. 14-1b) presents the plan of a bridge. Broadly, a bridge can be divided into two major parts, superstructure and substructure. The superstructure of a bridge is analogous to a single storey building roof and substructure to
that of the walls, columns and foundations supporting it.
● 2. Types of bridges
● 2.1 Arch bridge
Arch bridges are often used because of their pleasing appearances. These are more graceful and suited for deep gorge with rocky abutments. Arch bridges can be economically adopted up to a span of 250m. In this type of bridge, the roadway is constructed on an arch which rests on piers and abutments. An example of an arch bridge is the rainbow bridge across Niagara river over a span of 290m.
Unit 15 Bridge Superstructure
1. Steel superstructure types
Steel superstructures should be considered for any span length from 20 to 650FT or more. Generally, the following table (Table 15-1) can be used as a guideline for selecting steel superstructure types.
● 2. Concrete superstructure types
…
Concrete compressive strengths for commonly used precast beams shall be no more than 6000 PSI at release with a final compressive strength of 8000 PSI. High strength concrete (HSC) should also be considered when determining possible concrete superstructure alternatives.…
Precast beams may be designed using high strength concrete with a final compressive strength of up to 10000 PSI and a release strength of up to 9000 PSI with approval of the Director of the Engineering Division. HSC allows engineers to: design structures with smaller beams when clearance criteria needs to be met, reduce dead loads for more cost efficient substructures, and increase span lengths over conventional concrete.
Unit 16 Bridge Substructure
● 1 Piers
● 1.1 Pier types
Piers are intermediate supports in a multi-span bridge system. All feasible pier types must be considered in the preliminary phases of the project.
● 1.1.1 Cap-and-column type piers
Cap-and-column type piers have two or more circular or rectangular columns connected on top with a cap (a reinforced concrete beam that supports the superstructure). Generally, the pier cap ends will be cantilevered. For columns greater than 100 to 150 FT, the use of a compression strut at mid-height, similar to the pier cap, shall be investigated. The individual columns will be supported on an appropriate foundation.
● 2. Abutments
● 2.1 Abutment types
Abutments are structures positioned at the beginning and end of a bridge, which support the superstructure and approach roadway and retains the earth embankment. Abutments can be classified into the following five types:
wall abutment, pedestals, stub abutment, integral abutment, semi-integral abutment Unit 20 Construction Management and Cost Estimate
● 1. The planning process
Planning is the process of considering alternatives and methods to complete a task.
Planning creates an orderly sequence of events, defines the principles to be followed in carrying forth the plan, and describes the ultimate disposition of the results. It serves the manager by pointing out the things to be done, their sequence, how long each task should take, and who is responsible for which tasks or actions.
2. Activities
A common technique used to understand and organize complex undertakings is to break the p roject into smaller pieces (divided into subparts), Taylor’s concept. In construction this technique is applied in both planning and estimating. To create a construction plan all of the work tasks necessary to accomplish the project are first identified. …
● 3. Bar chart
In 1917, Henry L. Gantt invented a chart scheduling method. A Gantt chart (see Fig. 20.1) presented planned activities as stacked horizontal bands against a background of dates (along the horizontal axis). This Gantt or bar chart is the most commonly used project planning and control tool. …
● 4. Critical path method
The CPM focuses management’s attention on the relationships between critical activities. It is an activity relationship representation of the project. The evaluation of critical tasks, those that control project duration, allows for the determination of project duration. …
● 5. Activity logic network
The activity logic network benefits the manager by providing a graphical picture of the sequence of construction tasks. Before the diagram can be developed, the project must first be constructed mentally to determine activity relationships.
● 6. Critical path and critical activity
The critical path through a schedule network is the longest time duration path through the network. It establishes the minimum overall project time duration. All activities on the critical path are by definition critical. A critical activity can be determined from the logic network by applying either of these rules:
… …
Unit 21 Tendering and Contract
Everyone involved in construction must understand contracts – the sections of the contract itself, such as the agreement and the specifications and other required contract documents such as bonds and insurance – and the processes involved in con tract administration. …
● 1. Description of a contract
The makeup of a contract, whether the owner is a public agency or a private corporation, is essentially the same. The form of the document may change, but the elements of the contracts are the same.
● 2. Essential contract document
There are many documents that make up a construction contract. The four essential documents are:
2.1 Agreement
2.2 General condition
2.3 Supplementary condition
2.4 Specifications
● 3. The bit process
3.1 Inviting to bid
Government projects must be advertised, and are normally awarded to the low responsive bidder. Private projects do not need to be advertised and are usually negotiated, with only a limited number of selected contractors involved in the negotiation. …
3.2 Bidding
Bids must be submitted on time, at the location specified, on the correct forms, with acknowledgement of all addenda, and with a valid bid bond. Otherwise the bids are considered nonresponsive and are returned unopened. …
秋风词三五七言
秋风清，秋月明，
落叶聚还散，寒鸦栖复惊。
相亲相见知何日，此时此也难为情。
入我相思门，知我相思苦。
长相思兮长相忆，短相思系无穷极。
早知如此绊人心，何如当初莫相识。
道路桥梁与渡河专业介绍 道路桥梁与渡河工程（公路工程） 本专业培养公路、城市道路及一般桥梁方面的高级工程技术人才。要求学生获得以下几方面的知识和能力：公路与城市道路勘测设计、施工、监理、养护与管理，常用桥梁设计与施工及交通工程方面的基本知识和能力，公路与城市道路方面的基本科学研究能力。 毕业生主要在交通或城建部门从事本专业的勘测、设计、施工、监理、管理和科学研究工作，以及从事大专院校的本专业教学工作。学制四年。授予工学学士学位。 本专业培养桥梁方面的高级工程技术人才。要求学生获得以下几方面的知识和能力：桥梁的设计、施工、监理、维护与管理以及科学研究的基本技能。 毕业生主要在交通、城建或其它部门的交通基建系统，从事桥梁工程方面的勘测、设计、施工、监控、管理和科学研究工作，以及从事大专院校的本专业教学工作。学制四年。授予工学学士学位。 道路桥梁与渡河工程（岩土与隧道工程） 本专业培养公路隧道工程与岩土工程方面的高级工程技术人才。主要学习公路隧道与岩土工程勘测、设计、施工和管理方面的基础理论及专业知识，要求学生具备从事公路隧道与岩土工程勘测、设计、施工、养护管理及科学研究的能力。毕业生主要在交通部门或城建部门从事公路隧道工程与岩土工程勘测、设计、科研、施工及养护管理工作，以及从事大专院校的本专业教学工作。学制四年。授予工学学士学位。 道路桥梁与渡河工程（基地班） 本专业培养公路、城市道路、桥梁及隧道方面的高级工程技术人才。要求学生获得以下几方面的知识和能力：公路与城市道路勘测设计、桥梁设计、公路隧道与地下结构勘测设计及施工、养护与管理方面的基本知识；具备科学研究的基本技能、解决工程技术问题的科学研究能力。 本科毕业授予工学学士学位，其中优秀学生免试进入硕士研究生阶段学习。毕业生主要在交通或城建部门从事本专业的勘测、设计、施工、管理和科学研究工作，以及从事大专院校的本专业教学工作。
南昌大学 第五课 Traffic Engineering Introduction交通工程学概论 A.Text: Traffic Engineering Basics B.Reading Material: Highway Capacity Text Traffic Engineering Basics 1 Prediction of Traffic V olume Growth交通量增长预测 Traffic volume growth may be predicted using a number of methods but the two primary ones are the use of the ARTS long-range plan and manual methods. The ARTS plan may be used to establish average daily traffic volumes for streets within a study area for a future year as predicted by the ARTS model. This data can be used to develop a factor to apply to existing traffic counts to predict future-year traffic volumes. 使用了一些方法，可以预测交通量的增长，但两个主要的是远距离的艺术计划和手动的方法使用。艺术计划可能被用来建立一个研究区域内的街道由艺术模型预测未来一年的平均日均车流量。这些数据可以被用来开发适用于现有的交通计数的一个因素来预测未来年的交通量。 Manual extrapolation of existing data using growth factors may be available from the City, or the consultant may need to develop them. Growth factors may be and can be representative of a number of algebraic trends. Among these are the straight-line, exponential, and decaying-rate exponential trends. For a good discussion of these trend methods, see the Trip Forecasting Manual published by the Florida Department of Transportation. Generally, manual extrapolation of turning movement counts will not be accepted for periods of time exceeding five years. 手动现有数据推算，使用生长因子可能是从化市或顾问可能需要开发它们。生长因子可能是可以代表一些代数趋势。其中有直线，指数，腐烂率指数趋势。对于这些趋势的方法商量好了，看到的旅程预测佛罗里达运输部公布的手册。一般来说，手动外推转动计数将不被接受的时间周期超过五年。 2 Trip Generation Estimation 2出行生成估计 Trip generation may be estimated using the Institute of Transportation Engineers (ITE) Trip Generation. An accompanying publication, the Trip Generation Handbook provides additional information on how to use Trip Generation and how to apply adjustments such as pass-by trips.
Unit 1 Text A How Difficult Is English? 英语有多难 Like the national push for Asian literacy （n.有文化，有教养，有读写能力）in Australia，就如澳大利亚在全国推行学亚洲语言一样，there has been foreign languages fervor[f??v?] in China，中国也掀起一股外语热，with English on top of the list. 在这股热潮中，英语高居榜首。English is not only taught at schools，colleges and universities，but also at evening classes，on radio and TV．不仅各级学校教英语，夜校、电台、电视台也都设有英语课程。Parents hire private tutors for their school children；父母为学龄的孩子聘请英语家教，adult English learners would sacrifice the weekend at an English corner in a public park practicing their spoken English with peop1e of the same interest and determination. 成年英语学习者会牺牲周末休息日，到公园参加英语角，与志趣相投的英语学习者练习口语。Is English such a difficult language that it really demands people to invest a large amount of time and energy before it is mastered ? 英语真的有这么难，需要人们投入大量的时间和精力才能掌握吗? The answer，if I am asked to offer，is undoubtedly，yes．如果我被问及这个问题，那么毫无疑问，我的答案是：是的。From my personal experience, 从我个人的经验来看，I think learning English means far more than learning its pronunciation，its grammatical rules，its words，etc．英语学习不仅仅是学习英语发音、语法规则、词汇等，It involves learning everything about the countries where it is used and the people who use it．它包括学习与使用该语言的国家和民族有关的所有内容。Without such a complete understanding of the language, 对英语没有这样全面的理解，the English a foreigner speaks will inevitably sound strange or even unintelligible though there is not anything wrong with his pronunciation，sentence structure and the words he uses．即使发音、句子结构、措辞毫无错误，一个外国人所讲的英语也难免听起来稀奇古怪甚至难以理解。The social customs and habits of the English-speaking people contribute a lot to the difficulty a foreigner has in learning it．讲英语民族者的社会风俗习惯增加了外国人学习英语的难度。Take the Chinese English learners for example．以学英语的中国人为例，" Hello "and "Good morning" may sound a little bit simple to Chinese people．"你好"和"早上好"是非常简单的。It is totally beyond the understanding of a Chinese English learner that native English speakers would be annoyed when they're addressed "Where are you going?"，which is a commonly used addressing among the Chinese．"你去哪儿?"是中国人常用的问候语，若英语母语者被问及"你去哪儿?"，他们会因此感到不悦，这一点让中国的英语学习者大为不解。Is there anything wrong with the English sentence structure ? 这个英语句子结构不对吗? Of course not．当然不是。It takes quite some time for a Chinese English learner to understand the western concept of privacy being violated in this address. 学英语的中国人得费点儿时间才能理解这一问候语侵犯了西方人的隐私。By the same token，同样，"Have you eaten?"(which is another addressing term the Chinese people usually use)will sound to native English speakers that the Chinese are so hospitable that they invite people to meals off-handedly. 英语母语者听到"你吃了吗?"(中国人常用的另外一个问候语)，会觉得中国人非常好客，会在事先毫无准备的情况下请人吃饭。Meanwhile，the Chinese would be shocked to hear，"Oh，it's very nice of you．When?"，if the addressee happens to have a craving for Chinese cooking and has not had his dinner yet.如果听话者此刻正希望品尝一下中国美食，又碰巧没有吃饭，他会回答"太好了，什么时候?"，中国人为此也会大吃一惊。 "We can say we are going to have chicken for dinner．Why can't we say pig，bull or sheep for dinner instead of pork，beef or mutton?" Chinese English learners may raise such questions．中国的英语学习者可能会这样问："我们可以说吃鸡，为什么不能说吃猪、吃牛、吃羊，而要说吃猪肉、牛肉、羊肉呢?"Figuring out the reasons for the peculiar English vocabulary is no easy task for Chinese English learners．对学习英语的中国人来说，为这些特殊的英语词汇找出理由并非易事。But the problem is that memorizing English words mechanically would be devastating and inefficient if they did not know what had happened in British history．问题在于如果不懂英国历史，死记硬背英语单词毫无效率。Thus learning English(and other languages as well)involves learning the history of the countries where it is spoken．所以说，学英语(其他语言亦如此)还包括学习使用该语言国家的历史知识。A task of this kind is more difficult for Chinese English learners than for people who speak
第十四课亦爱亦恨话纽约 托马斯·格里非斯 1．那些赞美“大苹果”的广告活动，还有那些印着带有“我爱纽约”字样的心形图案的T恤衫，只不过是它们在绝望中发出悲哀的迹象，只不过是纽约这个非凡的城市日趋衰落的象征。纽约过去从不自我炫耀，而只让别的城市去这样做，因为自我炫耀显得“小家子气”。纽约既然是独一无二的、最大的而且是最好的城市，也就没有必要宣称自己是如何与众不同了。 2．然而，今日的纽约再不是头号城市了。至少，在开创时尚、领导潮流方面，纽约是再也配不上这个称号了。今日的纽约非但常常跟不上美国政治前进的步伐，而且往往也合不上美国人生活情趣变化的节拍。过去有一个时期，它曾是全国流行服装款式方面无可争议的权威，但由于长期抵制越来越流行的休闲服装款式而丧失了其垄断地位。纽约已不再是众望所归、纷起仿效的对象了，如今它甚至以成为风行美国的时装潮流的抵制者，以成为摆脱全国清一色的单调局面的一隅逃遁之地面自鸣得意。 3．纽约无力保持排头兵的地位这一点已是越来越明显了。有十多座其他城市都已经有了一些在建筑艺术上很富有创造性的建筑物，·而纽约最近二十年来所造的任何一幢建筑物都不能与之相比。曾是托斯卡尼尼全国广播公司交响乐团演出场所的巨人般的曼哈顿电视演播厅，现在经常是空无一人，而好莱坞大量生产出的情景喜剧和约翰尼·卡森节目的实况转播却占满了加利福尼亚的广播电视发送频道。美国流行歌曲创作发行中心从纽约的廷潘胡同转移到了纳什维尔和好莱坞。拉斯韦加斯的赌场经常出高薪聘请曼哈顿没有哪一家夜总会请得起的歌手和艺员。而体育运动方面，那些规模较大的体育馆、比较激动人心的球队以及热情最高的球迷们，往往都出现在纽约以外的地方。 4．纽约从来都不是召集会议的好场所——因为那儿少友情，不安全，人口拥挤，消费高昂——但现在它似乎正在一定程度上争回其作为旅游胜地的地位。即便如此，大多数美国人对新奥尔良、旧金山、华盛顿或迪斯尼乐园等地的评价可能还是高于纽约。人们普遍认为，还有十几座其他城市，包括我的家乡西雅图，都比纽约更适于居住。 5．那么，为什么有许多欧洲人称纽约是他们最喜爱的城市呢?他们比大多数美国人更欣赏纽约这个国际大都市的五彩缤纷的生活，它那残存的、独此一家的欧洲社会准则以及它那众多外来民族混杂而居的社会。这些欧洲人中有些人也许是因为在麦迪逊大街和第五大街这两条双胞胎似的繁华大街上看到那些熟悉的国际名牌商号—口g6些专为迎合并蒙骗那些轻浮浅薄的有钱人而存在的珠宝店、鞋店和服装设计店——而感到心头踏实。然而事实并非如此，最令欧洲人激动不已的是这个城市的那种精神饱满的紧张气氛和它那种野性的活力。 6．纽约充满着活力、竞争和奋斗。同时，由于存在着一批能说会道的失意者，它也充满着嘲笑、轻侮和失意者的心灰意冷(“你说该咋办?”)。它充满着无休无止的斗争——为了地铁上的座位，为了引起一个的士司机、一个办事员或一个侍者的注意，为了有一个立足之地，
路桥工程 第一讲道路与桥梁基本知识 【考点】高等级公路组成 一般由路基、路面、桥梁、隧道工程和交通工程设施等几大部分组成。 1、路基工程 路基是用土或石料修筑而成的线形结构物。它承受着本身的岩土自重和路面重力，以及由路面传递而来的行车荷载，是整个公路构造的重要组成部分。公路路基主要包括路基体、边坡、边沟及其它附属设施等几个部分，各部分名称如图1-1所示。 路基设计洪水频率 2、路面工程 路面是用各种筑路材料或混合料分层铺筑在公路路基上供汽车行驶的层状构造物。其作用是保证汽车在道路上能全天候、稳定、高速、舒适、安全和经济地运行。 路面通常由路面体、路肩、路缘石及中央分隔带等组成。其中路面体在横向又可分为行车道、人行道及路缘带，如图1-2所示。路面体按结构层次自上而下可分为面层、基层、垫层或联结层等。 3、桥隧工程 桥隧工程是高等级公路中的重要组成部分，它包括桥梁、涵洞、通道和隧道等。 桥梁的组成 桥梁由两个主要部分组成： （一）桥跨结构（或称桥孔结构，上部结构），是在线路遇到障碍而中断时，跨越障碍的主要承重结构。 （二）桥墩、桥台、墩台基础（统称下部结构），是支承桥跨结构并将恒载和车辆等荷载传至地基的建筑物。 桥台设在桥的两端，桥墩则在两桥台之间。桥台除了支承桥跨结构的作用外，还要防止路堤滑坡，并与路堤衔接。为保护桥头路堤填土，每个桥台两侧常做成石砌的锥体护坡。 墩台基础，是埋入土层之中，并使桥上全部荷载传至地基的结构部分。 在桥跨结构与墩台之间，还需设置支座，它不仅要传递荷载，而且根据结构体系的不同，保证桥跨结构能产生一定的变位。 除上述基本结构外，桥梁还常常建造一些附属结构物，如护坡、护岸、挡土墙、导流结构物、检查设备等。 在桥梁规划和设计中，设计洪水位、计算跨径、标准跨径、桥长、桥梁净跨径、桥梁的建筑高度等均为主要的桥梁技术指标。 净跨径：对于梁式桥是指设计洪水位上相邻两个桥墩（桥台）之间的净距，用L0表示；对于拱式桥是每孔拱跨两个拱脚截面最低点之间的水平距离。 计算跨径：对于具有支座的桥梁，是指桥跨结构相邻两个支座中心之间的距离，用 1表示。对于图1所示的拱式桥，是两相邻拱脚截面形心点之间的水平距离，或拱轴线两端点之间的水平距离。桥跨结构的力学计算是以 1为基准的。总跨径在多孔桥梁中，各孔净跨径的总和，也称桥梁孔径（），它反映了桥下宣泄洪水的能力。
Lesson 7 Transportation Systems交通运 输系统 Transportation system in a developed nation consists of a network of modes that have evolved over many years. The system consists of vehicles, guideways, terminal facilities and control systems: these operate according to established procedures and schedules in the air, on land, and on water. The system also requires interaction with the user, the operator and the environment. The systems that are in place reflect the multitude of decisions made by shippers, carriers, government, individual travelers, and affected nonusers concerning the investment in or the use of transportation. The transportation system that has evolved has produced a variety of modes that complement each other. 在发达国家，交通运输系统由网状结构组成的模式已经发展了好多年。这个系统由交通工具、轨道、站场设施和控制系统组成。这些依照空中、陆上和水上已制定的程序和计划运转。这个系统也需要和用户、司机和环境互动。现在的运输体系可以反映出与投资和使用有关的多方决定，包括运输业主、承运商、政府、每个出行者以及受影响的非使用者等。逐步发展的交通运输系统形成了各种互补模式。 The U. S. transportation system today is a highly developed, complex network of modes and facilities that furnishes shippers and travelers with a wide range of choices in terms of services provided. Each mode offers a unique set of service characteristics in terms of travel time, frequency, comfort, reliability, convenience and safety. The term level of service is used to describe the relative values of these attributes. The traveler or shipper must compare the level of service offered with the cost in order to make tradeoffs and mode selection. Furthermore, a shipper or traveler can decide to use a public carrier or to use private (or personal) transportation. For example, a manufacturer can ship goods through a trucking firm or with company trucks, a homeowner who has been relocated can hire a household moving company or rent a truck, and a commuter can elect to ride the bus to work or drive a car. Each of these decisions involves a complex set of factors that require
Unit1 1.背离传统需要极大的勇气 1) It takes an enormous amount of courage to make a departure from the tradition. 2.汤姆过去很腼腆，但这次却非常勇敢能在大庭广众面前上台表演了。 2) Tom used to be very shy, but this time he was bold enough to give a performance in front of a large audience. 3.很多教育家认为从小培养孩子的创新精神是很可取的。 3) Many educators think it desirable to foster the creative spirit in the child at an early age. 4.假设那幅画确实是名作，你觉得值得购买吗？ 4) Assuming (that) this painting really is a masterpiece, do you think it’s worthwhile to buy/purchase it? 5.如果这些数据统计上市站得住脚的，那它将会帮助我们认识正在调查的问题。 5) If the data is statistically valid, it will throw light on the problem we are investigating. Unit2 1.该公司否认其捐款有商业目的。 1) The company denied that its donations had a commercial purpose.
Never, ever give up! 永不言弃！ 1 As a young boy, Britain's great Prime Minister, Sir Winston Churchill, attended a public school called Harrow. He was not a good student, and had he not been from a famous family, he probably would have been removed from the school for deviating from the rules. Thankfully, he did finish at Harrow and his errors there did not preclude him from going on to the university. He eventually had a premier army career whereby he was later elected prime minister. He achieved fame for his wit, wisdom, civic duty, and abundant courage in his refusal to surrender during the miserable dark days of World War II. His amazing determination helped motivate his entire nation and was an inspiration worldwide. 英国的伟大首相温斯顿·丘吉尔爵士，小时候在哈罗公学上学。当时他可不是个好学生，要不是出身名门，他可能早就因为违反纪律被开除了。谢天谢地，他总算从哈罗毕业了，在那里犯下的错误并没影响到他上大学。后来，他凭着军旅生涯中的杰出表现当选为英国首相。他的才思、智慧、公民责任感以及在二战痛苦而黑暗的时期拒绝投降的无畏勇气，为他赢得了美名。他非凡的决心，不仅激励了整个民族，还鼓舞了全世界。 2 Toward the end of his period as prime minister, he was invited to address the patriotic young boys at his old school, Harrow. The headmaster said, "Young gentlemen, the greatest speaker of our time, will be here in a few days to address you, and you should obey whatever sound advice he may give you." The great day arrived. Sir Winston stood up, all five feet, five inches and 107 kilos of him, and gave this short, clear-cut speech: "Young men, never give up. Never give up! Never give up! Never, never, never, never!" 在他首相任期即将结束时，他应邀前往母校哈罗公学，为满怀报国之志的同学们作演讲。校长说：“年轻的先生们，当代最伟大的演说家过几天就会来为你们演讲，他提出的任何中肯的建议，你们都要听从。”那个激动人心的日子终于到了。温斯顿爵士站了起来——他只有5英尺5英寸高，体重却有107公斤。他作了言简意赅的讲话：“年轻人，要永不放弃。永不放弃！永不放弃！永不，永不，永不，永不！” 3 Personal history, educational opportunity, individual dilemmas — none of these can inhibit a strong spirit committed to success. No task is too hard. No amount of preparation is too long or too difficult. Take the example of two of the most scholarly scientists of our age, Albert Einstein and Thomas Edison. Both faced immense obstacles and extreme criticism. Both were called "slow to learn" and written off as idiots by their teachers. Thomas Edison ran away from school because his teacher whipped him repeatedly for asking too many questions. Einstein didn't speak fluently until he was almost nine years old and was such a poor student that some thought he was unable to learn. Yet both boys' parents believed in them. They worked intensely each day with their sons, and the boys learned to never bypass the long hours of hard work that they needed to succeed. In the end, both Einstein and Edison overcame their childhood persecution and went on to achieve magnificent discoveries that benefit the entire world today. 个人经历、教育机会、个人困境，这些都不能阻挡一个全力以赴追求成功的、有着坚强意志的人。任务再苦，准备再长，难度再大，都不能让他放弃自己的追求。就以本时代最有学问的两位科学家——阿尔伯特·爱因斯坦和托马斯·爱迪生为例，他们都曾面临巨大的障碍和极
交通土建路桥工程专业求职简历范文 交通土建路桥工程专业求职简历范文 一份别出心裁的能够吸引招聘单位的注意，但是一定也要有一个能够吸引招聘单位的内容才可以。除了简历的制作精美别出心裁，内容也要有一定的特点，一些不起眼的细节部分的效果也能提高个人简历的整体质量。从简历的外观之作，到简历的各项内容，都是引起关注的`要点，代表应征者对工作的重视，以及良好积极的工作态度，这样就能够吸引招聘单位的注意力，增加就业机会。 个人简历除了一些细节上的制作，还需要一些重点的突出。比如一些个人经历以及在工作中获得的嘉奖，可以尽量放在简历的中上方，让招聘单位能够迅速注意到简历的重点，并且能在短时间内阅读完。因为招聘单位每天要阅读的简历很多，只有控制简历的内容精短，重点突出，利用少量的文字充分展示自我，才能在短时间内吸引招聘单位的注意力，获得就业机会。 下面是和大家分享的交通土建路桥工程专业求职，更多相关资讯请点击(. /jianli)。
国籍：中国 目前住地：广州民族：汉族 户籍地：吉林身高体重： 178 cm 75 kg 婚姻状况：已婚年龄： 34 岁 求职意向及工作经历 人才类型：普通求职 应聘职位：建筑/房地产/物业管理类：路桥经理(全国)、建筑/房地产/物业管理类：公司经理、 工作年限： 11 职称：中级 求职类型：全职可到职日期：随时 月薪要求： 8000--12000 希望工作地区：广东省江西湖南
工作经历：公司名称：起止年月：xx-01 ～ xx-04东莞生态园大道市政道路工程第七标段(k10+253-k12+277)(挂靠广东阳江建安集团有限公司) 公司性质：私营企业所属行业：房地产，建筑，安装，装潢 担任职务：项目经理 工作描述：软基处理:换填、抛石挤淤、深层水泥搅拌桩。 桥梁;中桥三座、冲孔灌注桩基础、20米空心板梁。 给水：球墨铸铁管。排水：Ⅱ级钢筋混凝土承插管。污水：玻璃钢夹砂管(钢板桩支护) 临时设施:钢管桩便桥2座。 总造价1.02亿元。 离职原因：工程竣工、老板没有后续工程(二次转包)
第二课 沥青及沥青混合料 Asphalt $ Mix Asphalt Text: Asphalt &Asphalt Paving Materials 1Asphalt Defined The black cementing agent known as asphalt has been used for road construction for centuries. Although there are natural deposits of asphalt , or rock asphalt , most used today is produced during the refining of crude oil. Asphalt is a constituent of most petroleums and is isolated through the refining process. Asphalt is called a bituminous material because it contains bitumen, a hydrocarbon material soluble in carbon disulfate. The tar obtained from the destructive distillation of soft coal also contains bitumen. Both petroleum asphalt and coal tar are referred to as bituminous materials. Because their properties differ greatly , petroleum asphalt should not be confused with coal tar . Petroleum asphalt is composed almost entirely of bitumen while the bitumen content in coal tar is relatively low. The two materials should be treated as separate entities. One of the characteristics and advantages of asphalt as an engineering construction and maintenance materials is its versatility. Although a semi-solid at ordinary temperratures , asphalt may be liquefied by applying heat, dissolving it in solvents, or emulsifying it. Asphalt is a strong cement that is readily adhesive and highly waterproof and durable, making it particularly useful in road building. It is also highly resistant to the actions of most acids, alkalis, and salts. 1.1Asphalt Binder Asphalt is produced in a variety of types and grades ranging from hard-brittle solids to near water-thin liquids. The semi-solid form known as asphalt binder is the basic material used in Hot-Mix Asphalt(HMA) pavements. Liquid asphalt is produced when asphalt binder is blended or “cut back” with petroleum distillates or emulsified with water and an emulsifying agent. At ambient air temperatures, asphalit binder is a black, sticky , highly viscous material. It is a strong and durable binder with excellent adhesive and waterproofing characteristics. Applying heat, which facilitates mixing with mineral aggregates to produce HMA , can readily liquefy asphalt binders. The largest use of asphalt binder is for HMA . After compacting and cooling to air temperature, HMA is a very strong material with the ability to sustain heavy traffic loads while remaining flexible enough to withstand ambient environmental conditions and stress. Over 96 percent of the hard-surfaced roads in the United States are paved using HMA. 1.2 Emulsified Asphalts Emulsified asphalts(also known as emulsions) are low-viscosity mixtures of tiny asphalt binder droplets, water and emulsifying agents. The emulsifying agent coats the surfaces of the asphalt droplets and keeps them suspended in the water prior to application. After application, the asphalt emulsion breaks and the water separates and evaporates. Emulsions are brownish in color during application, but after breaking, the asphalt binder returns to its original black color. Emulsions are used for a Tack Coat between subsequent layers of HMA to aid in binding the
Unit 1 1.她连水都不愿喝一口，更别提留下来吃饭了。(much less) She wouldn't take a drink, much less would she stay for dinner. 2.他认为我在对他说谎，但实际上我讲的是实话。(whereas) He thought I was lying to him, whereas I was telling the truth. 3.这个星期你每天都迟到，对此你怎么解释？(account for) How do you account for the fact that you have been late every day this week? 4.他们利润增长的部分原因是采用了新的市场策略。(due to) The increase in their profits is due partly to their new market strategy. 5.这样的措施很可能会带来工作效率的提高。(result in) Such measures are likely to result in the improvement of work efficiency. 6.我们已经在这个项目上投入了大量时间和精力，所以我们只能继续。(pour into) We have already poured a lot of time and energy into the project, so we have to carry on. Unit 2 1.尽管她是家里的独生女，她父母也从不溺爱她。(despite) Despite the fact that she is the only child in her family, she is never babied by her parents. 2.迈克没来参加昨晚的聚会，也没给我打电话作任何解释。(nor) Mike didn't come to the party last night, nor did he call me to give an explanation. 3.坐在他旁边的那个人确实发表过一些小说，但决不是什么大作家。(next to; by no means) The person sitting next to him did publish some novels, but he is by no means a great writer. 4.他对足球不感兴趣，也从不关心谁输谁赢。(be indifferent to) He has no interest in football and is indifferent to who wins or loses. 5.经理需要一个可以信赖的助手，在他外出时，由助手负责处理问题。(count on) The manager needs an assistant that he can count on to take care of problems in his absence. 6.这是他第一次当着那么多观众演讲。(in the presence of sb.) This is the first time that he has made a speech in the presence of so large an audience. Unit 3 1.你再怎么有经验，也得学习新技术。(never too... to...) You are never too experienced to learn new techniques. 2.还存在一个问题，那就是派谁去带领那里的研究工作。(Use an appositional structure) There remains one problem, namely, who should be sent to head the research there. 3.由于文化的不同，他们的关系在开始确实遇到了一些困难。(meet with) Their relationship did meet with some difficulty at the beginning because of cultural differences. 4.虽然他历经沉浮，但我始终相信他总有一天会成功的。(ups and downs; all along) Though he has had ups and downs, I believed all along that he would succeed someday. 5.我对你的说法的真实性有些保留看法。(have reservations about) I have some reservations about the truth of your claim.