土木工程专业建筑防火设计大学毕业论文外文文献翻译及原文

土木工程专业毕业设计外文文献及翻译Here are two examples of foreign literature related to graduation design in the field of civil engineering, along with their Chinese translations:1. Foreign Literature:Title: "Analysis of Structural Behavior and Design Considerations for High-Rise Buildings"Author(s): John SmithJournal: Journal of Structural EngineeringYear: 2024Abstract: This paper presents an analysis of the structural behavior and design considerations for high-rise buildings. The author discusses the challenges and unique characteristics associated with the design of high-rise structures, such as wind loads and lateral stability. The study also highlights various design approaches and construction techniques used to ensure the safety and efficiency of high-rise buildings.Chinese Translation:标题：《高层建筑的结构行为分析与设计考虑因素》期刊：结构工程学报年份：2024年2. Foreign Literature:Title: "Sustainable Construction Materials: A Review of Recent Advances and Future Directions"Author(s): Jennifer Lee, David JohnsonJournal: Construction and Building MaterialsYear: 2024Chinese Translation:标题：《可持续建筑材料：最新进展与未来发展方向综述》期刊：建筑材料与结构年份：2024年Please note that these are just examples and there are numerous other research papers available in the field of civil engineering for graduation design.。

外文资料来源及题目（注：含作者、书名、杂志名或外文数据库名等，英文文章或段落标题，原文附后）题目 : Discussion on the fire safety design of a high-risebuilding作者 :马钱丽郭伟摘自 : Elsevier电子期刊全文库关于一幢高层建筑的消防安全设计的研究马钱利a郭伟ba 滨海新区分公司消防队中国天津滨海新区中心路7 号 300457b 天津消防和安全科学研究所中国天津南开区魏晋南路 110 号 30387摘要：高层住宅建筑在消防安全设计上的几个问题：疏散楼梯和电梯不能从顶部运行到地上，居民无法转移到建筑物外; 消防电梯不能直接到达一楼和剪刀型楼梯与消防电梯的合用大厅。

基于这些问题 , 提出消防安全目标并提供了解决方案。

希望，建议的解决方案可以为类似的高层建筑的消防安全设计提供参考。

关键词：高层住宅建筑；消防设计；消防电梯1.引言“11.15 ”上海灾难性的火灾引起了人们对高层住宅建筑消防安全的思考。

这次灾难是由于节能项目建设引起，而不是因为高层设计本身。

然而 , 如何提高消防安全的高层住宅建筑和维护的生命安全居民已成为最重要的问题，必须认真考虑在这类高层建筑上的消防安全设计。

因此，分析了我国北方的一幢高层建筑的消防安全设计，以它为例子来为同类建筑的消防安全设计提供参考。

2.高层建筑的火灾风险因素通常高层住宅建筑火灾风险包括以下:2.1 火和烟雾的快速扩散因为高层建筑的“烟囱效应”，如果控制措施不够，火和烟会通过楼梯、电梯和管道在短时间内快速的蔓延到楼上。

2.2 火灾扑救困难类似于建筑的高度，不完善的消防设备和过大的离地距离，给灭火增加了难度。

此外，中国目前的高层建筑大部分的电力器材都是可燃的，这大大增加了大火的垂直蔓延速度。

这样，大火覆盖了建筑的外表面，为消防员的灭火增加了难度。

2.3 居民逃生困难一般来说，高层建筑居民要比低层建筑居民多，另外，高层建筑高度大使得疏散更加困难。

译文译文：：建筑建筑防火设计防火设计防火设计拉格夫拉格夫摘要：这篇论文主要研究建筑的防火设计，火作用于建筑与重力荷载,风荷载,地震力等作用于建筑物结构上有很大不同。

火是由人类活动或者机械故障，建筑物内的电器引起的1.1.介绍介绍介绍其他论文，考虑建筑物的设计的重力荷载，风和地震等一系列问题。

建筑物针对这些负载的影响的设计是相当大的程度上涵盖了工程的标准参照了建筑法规。

几乎在同一程度上，万一发生火灾，事实并非如此。

相反，正是如澳大利亚建筑法那样的法规明确了建筑防火安全的标准，如用as3600,as4100的方法确定耐火构件。

本文的目的就是要从工程角度考虑建筑设计消防安全，（如目前所做的风力或地震等其他荷载），同时将这种方法应用于当前规范要求的环境之中。

首先需要指出的是，设计一幢防火大楼只考虑建设结构或者是否有足够的结构性是远远不够的。

这是因为火可以直接通过烟雾和热量影响住户，还可以蔓延增加严重性，而其它对楼房的影响不具备这一特征。

尽管有这些评论，本文的大部分重点仍将集中于建筑结构的设计问题。

本文将选择一栋大楼的两种情况作为讨论的对象。

图1所示的多层办公楼利用了转换结构，跨过了一条铁路路轨。

这是在假定了广泛的轨道交通利用这些轨道基础上，考虑到了运费和内燃机车。

我们将从从消防安全角度考虑第一种情况，即转换结构。

这是被称为情况1，其中的关键问题是: 哪一级耐火要求用这种转换结构？这种转换结构又如何确定？这种情况已经选定，因为它显然不属于大多数建筑法规的正常的监管范围。

我们需要的是一项工程性的而不是指令性的解决办法。

第二种火灾形势（称为情况2）相应的消防局内不同层次的建设和涵盖了建筑法规。

选择这种情况是因为它将促成工程学方法的讨论以及如何把这些建设规章相衔接,因为两种工程和指令性的办法皆是可行的。

2.火灾的独特性2.火灾的独特性火灾的独特性介绍2.1介绍设计师无法控制风和地震等"自然"的现象，因而只能根据历史记载更合理的选择建筑物的位置，或者提高建筑的负荷能力。

The bridge crack produced the reason to simply analyseIn recent years, the traffic capital construction of our province gets swift and violent development, all parts have built a large number of concrete bridges. In the course of building and using in the bridge, relevant to influence project quality lead of common occurrence report that bridge collapse even because the crack appears The concrete can be said to " often have illness coming on " while fracturing and " frequently-occurring disease ", often perplex bridge engineers and technicians. In fact , if take certain design and construction measure, a lot of cracks can be overcome and controlled. For strengthen understanding of concrete bridge crack further, is it prevent project from endanger larger crack to try one's best, this text make an more overall analysis , summary to concrete kind and reason of production , bridge of crack as much as possible, in order to design , construct and find out the feasible method which control the crack , get the result of taking precautions against Yu WeiRan.Concrete bridge crack kind, origin cause of formation In fact, the origin cause of formation of the concrete structure crack is complicated and various, even many kinds of factors influence each other , but every crack has its one or several kinds of main reasons produced . The kind of the concrete bridge crack, on its reason to produce, can roughly divide several kinds as follows :(1) load the crack caused Concrete in routine quiet .Is it load to move and crack that produce claim to load the crack under the times of stress bridge, summing up has direct stress cracks , two kinds stress crack onces mainly. Direct stress crack refer to outside load direct crack that stress produce that cause. The reason why the crack produces is as follows, 1, Design the stage of calculating , does not calculate or leaks and calculates partly while calculating in structure; Calculate the model is unreasonable; The structure is supposed and accorded with by strength actually by strength ; Load and calculate or leak and calculate few; Internal force and matching the mistake in computation of muscle; Safety coefficient of structure is not enough. Do not consider the possibility that construct at the time of the structural design; It is insufficientto design the section; It is simply little and assigning the mistake for reinforcing bar to set up; Structure rigidity is insufficient; Construct and deal with improperly; The design drawing can not be explained clearly etc.. 2, Construction stage, does not pile up and construct the machines , material limiting ; Is it prefabricate structure structure receive strength characteristic , stand up , is it hang , transport , install to get up at will to understand; Construct not according to the design drawing, alter the construction order of the structure without authorization , change the structure and receive the strength mode; Do not do the tired intensity checking computations under machine vibration and wait to the structure . 3, Using stage, the heavy-duty vehicle which goes beyond the design load passes the bridge; Receive the contact , striking of the vehicle , shipping; Strong wind , heavy snow , earthquake happen , explode etc.. Stress crack once means the stress of secondary caused by loading outside produces the crack. The reason why the crack produces is as follows, 1, In design outside load function , because actual working state and routine , structure of thing calculate have discrepancy or is it consider to calculate, thus cause stress once to cause the structure to fracture in some position. Two is it join bridge arch foot is it is it assign " X " shape reinforcing bar , cut down this place way , section of size design and cut with scissors at the same time to adopt often to design to cut with scissors, theory calculate place this can store curved square in , but reality should is it can resist curved still to cut with scissors, so that present the crack and cause the reinforcing bar corrosion. 2, Bridge structure is it dig trough , turn on hole , set up ox leg ,etc. to need often, difficult to use a accurate one diagrammatic to is it is it calculate to imitate to go on in calculating in routine, set up and receive the strength reinforcing bar in general foundation experience. Studies have shown , after being dug the hole by the strength component , it will produce the diffraction phenomenon that strength flows, intensive near the hole in a utensil, produced the enormous stress to concentrate. In long to step prestressing force of the continuous roof beam , often block the steel bunch according to the needs of section internal force in stepping, set up the anchor head, but can often see the crack in the anchor firm section adjacent place. So if deal with improper, in corner or component form sudden change office , block place to be easy to appear crack strengthreinforcing bar of structure the. In the actual project, stress crack once produced the most common reason which loads the crack. Stress crack once belong to one more piece of nature of drawing , splitting off , shearing. Stress crack once is loaded and caused, only seldom calculate according to the routine too, but with modern to calculate constant perfection of means, times of stress crack to can accomplish reasonable checking computations too. For example to such stresses 2 times of producing as prestressing force , creeping ,etc., department's finite element procedure calculates levels pole correctly now, but more difficult 40 years ago. In the design, should pay attention to avoiding structure sudden change (or section sudden change), when it is unable to avoid , should do part deal with , corner for instance, make round horn , sudden change office make into the gradation zone transition, is it is it mix muscle to construct to strengthen at the same time, corner mix again oblique to reinforcing bar , as to large hole in a utensil can set up protecting in the perimeter at the terms of having angle steel. Load the crack characteristic in accordance with loading differently and presenting different characteristics differently. The crack appear person who draw more, the cutting area or the serious position of vibration. Must point out , is it get up cover or have along keep into short crack of direction to appear person who press, often the structure reaches the sign of bearing the weight of strength limit, it is an omen that the structure is destroyed, its reason is often that sectional size is partial and small. Receive the strength way differently according to the structure, the crack characteristic produced is as follows: 1, The centre is drawn. The crack runs through the component cross section , the interval is equal on the whole , and is perpendicular to receiving the strength direction. While adopting the whorl reinforcing bar , lie in the second-class crack near the reinforcing bar between the cracks. 2, The centre is pressed. It is parallel on the short and dense parallel crack which receive the strength direction to appear along the component. 3, Receive curved. Most near the large section from border is it appear and draw into direction vertical crack to begin person who draw curved square, and develop toward neutralization axle gradually. While adopting the whorl reinforcing bar , can see shorter second-class crack among the cracks. When the structure matches muscles less, there are few but wide cracks, fragility destruction may take place in thestructure 4, Pressed big and partial. Heavy to press and mix person who draw muscle a less one light to pigeonhole into the component while being partial while being partial, similar to receiving the curved component. 5, Pressed small and partial. Small to press and mix person who draw muscle a more one heavy to pigeonhole into the component while being partial while being partial, similar to the centre and pressed the component. 6, Cut. Press obliquly when the hoop muscle is too dense and destroy, the oblique crack which is greater than 45?? direction appears along the belly of roof beam end; Is it is it is it destroy to press to cut to happen when the hoop muscle is proper, underpart is it invite 45?? direction parallel oblique crack each other to appear along roof beam end. 7, Sprained. Component one side belly appear many direction oblique crack, 45?? of treaty, first, and to launch with spiral direction being adjoint. 8, Washed and cut. 4 side is it invite 45?? direction inclined plane draw and split to take place along column cap board, form the tangent plane of washing. 9, Some and is pressed. Some to appear person who press direction roughly parallel large short cracks with pressure.(2) crack caused in temperature changeThe concrete has nature of expanding with heat and contract with cold, look on as the external environment condition or the structure temperature changes, concrete take place out of shape, if out of shape to restrain from, produce the stress in the structure, produce the temperature crack promptly when exceeding concrete tensile strength in stress. In some being heavy to step foot-path among the bridge , temperature stress can is it go beyond living year stress even to reach. The temperature crack distinguishes the main characteristic of other cracks will be varied with temperature and expanded or closed up. The main factor is as follows, to cause temperature and change 1, Annual difference in temperature. Temperature is changing constantly in four seasons in one year, but change relatively slowly, the impact on structure of the bridge is mainly the vertical displacement which causes the bridge, can prop up seat move or set up flexible mound ,etc. not to construct measure coordinate , through bridge floor expansion joint generally, can cause temperature crack only when the displacement of the structure is limited, for example arched bridge , just bridge etc. The annual difference in temperature of our country generally changes therange with the conduct of the average temperature in the moon of January and July. Considering the creep characteristic of the concrete, the elastic mould amount of concrete should be considered rolling over and reducing when the internal force of the annual difference in temperature is calculated. 2, Rizhao. After being tanned by the sun by the sun to the side of bridge panel , the girder or the pier, temperature is obviously higher than other position, the temperature gradient is presented and distributed by the line shape . Because of restrain oneself function, cause part draw stress to be relatively heavy, the crack appears. Rizhao and following to is it cause structure common reason most , temperature of crack to lower the temperature suddenly 3, Lower the temperature suddenly. Fall heavy rain , cold air attack , sunset ,etc. can cause structure surface temperature suddenly dropped suddenly, but because inside temperature change relatively slow producing temperature gradient. Rizhao and lower the temperature internal force can adopt design specification or consult real bridge materials go on when calculating suddenly, concrete elastic mould amount does not consider converting into and reducing 4, Heat of hydration. Appear in the course of constructing, the large volume concrete (thickness exceeds 2. 0), after building because cement water send out heat, cause inside very much high temperature, the internal and external difference in temperature is too large, cause the surface to appear in the crack. Should according to actual conditions in constructing, is it choose heat of hydration low cement variety to try one's best, limit cement unit's consumption, reduce the aggregate and enter the temperature of the mould , reduce the internal and external difference in temperature, and lower the temperature slowly , can adopt the circulation cooling system to carry on the inside to dispel the heat in case of necessity, or adopt the thin layer and build it in succession in order to accelerate dispelling the heat. 5, The construction measure is improper at the time of steam maintenance or the winter construction , the concrete is sudden and cold and sudden and hot, internal and external temperature is uneven , apt to appear in the crack. 6, Prefabricate T roof beam horizontal baffle when the installation , prop up seat bury stencil plate with transfer flat stencil plate when welding in advance, if weld measure to be improper, iron pieces of nearby concrete easy to is it fracture to burn. Adopt electric heat piece draw law piece draw prestressing force at the component ,prestressing force steel temperature can rise to 350 degrees Centigrade , the concrete component is apt to fracture. Experimental study indicates , are caused the intensity of concrete that the high temperature burns to obviously reduce with rising of temperature by such reasons as the fire ,etc., glueing forming the decline thereupon of strength of reinforcing bar and concrete, tensile strength drop by 50% after concrete temperature reaches 300 degrees Centigrade, compression strength drops by 60%, glueing the strength of forming to drop by 80% of only round reinforcing bar and concrete; Because heat, concrete body dissociate ink evaporate and can produce and shrink sharply in a large amount(3) shrink the crack causedIn the actual project, it is the most common because concrete shrinks the crack caused. Shrink kind in concrete, plasticity shrink is it it shrinks (is it contract to do ) to be the main reason that the volume of concrete out of shape happens to shrink, shrink spontaneously in addition and the char shrink. Plasticity shrink. About 4 hours after it is built that in the course of constructing , concrete happens, the cement water response is fierce at this moment, the strand takes shape gradually, secrete water and moisture to evaporate sharply, the concrete desiccates and shrinks, it is at the same time conduct oneself with dignity not sinking because aggregate,so when harden concrete yet,it call plasticity shrink. The plasticity shrink producing amount grade is very big, can be up to about 1%. If stopped by the reinforcing bar while the aggregate sinks, form the crack along the reinforcing bar direction. If web , roof beam of T and roof beam of case and carry baseplate hand over office in component vertical to become sectional place, because sink too really to superficial obeying the web direction crack will happen evenly before hardenning. For reducing concrete plasticity shrink,it should control by water dust when being construct than,last long-time mixing, unloading should not too quick, is it is it take closely knit to smash to shake, vertical to become sectional place should divide layer build. Shrink and shrink (do and contract). After the concrete is formed hard , as the top layer moisture is evaporated progressively , the humidity is reduced progressively , the volume of concrete is reduced, is called and shrunk to shrink (do and contract). Because concrete top layermoisture loss soon, it is slow for inside to lose, produce surface shrink heavy , inside shrink a light one even to shrink, it is out of shape to restrain from by the inside concrete for surface to shrink, cause the surface concrete to bear pulling force, when the surface concrete bears pulling force to exceed its tensile strength, produce and shrink the crack. The concrete hardens after-contraction to just shrink and shrink mainly .Such as mix muscle rate heavy component (exceed 3% ), between reinforcing bar and more obvious restraints relatively that concrete shrink, the concrete surface is apt to appear in the full of cracks crackle. Shrink spontaneously. Spontaneous to it shrinks to be concrete in the course of hardenning , cement and water take place ink react, the shrink with have nothing to do by external humidity, and can positive (whether shrink, such as ordinary portland cement concrete), can negative too (whether expand, such as concrete, concrete of slag cement and cement of fly ash). The char shrinks. Between carbon dioxide and hyrate of cement of atmosphere take place out of shape shrink that chemical reaction cause. The char shrinks and could happen only about 50% of humidity, and accelerate with increase of the density of the carbon dioxide. The char shrinks and seldom calculates . The characteristic that the concrete shrinks the crack is that the majority belongs to the surface crack, the crack is relatively detailed in width , and criss-cross, become the full of cracks form , the form does not have any law . Studies have shown , influence concrete shrink main factor of crack as follows, 1, Variety of cement , grade and consumption. Slag cement , quick-hardening cement , low-heat cement concrete contractivity are relatively high, ordinary cement , volcanic ash cement , alumina cement concrete contractivity are relatively low. Cement grade low in addition, unit volume consumption heavy rubing detailed degree heavy, then the concrete shrinks the more greatly, and shrink time is the longer. For example, in order to improve the intensity of the concrete , often adopt and increase the cement consumption method by force while constructing, the result shrinks the stress to obviously strengthen . 2, Variety of aggregate. Such absorbing water rates as the quartz , limestone , cloud rock , granite , feldspar ,etc. are smaller, contractivity is relatively low in the aggregate; And such absorbing water rates as the sandstone , slate , angle amphibolite ,etc. are greater, contractivity is relatively high. Aggregate grains of foot-path heavy to shrink light inaddition, water content big to shrink the larger. 3, Water gray than. The heavier water consumption is, the higher water and dust are, the concrete shrinks the more greatly. 4, Mix the pharmaceutical outside. It is the better to mix pharmaceutical water-retaining property outside, then the concrete shrinks the smaller. 5, Maintain the method . Water that good maintenance can accelerate the concrete reacts, obtain the intensity of higher concrete. Keep humidity high , low maintaining time to be the longer temperature when maintaining, then the concrete shrinks the smaller. Steam maintain way than maintain way concrete is it take light to shrink naturall. 6, External environment. The humidity is little, the air drying , temperature are high, the wind speed is large in the atmosphere, then the concrete moisture is evaporated fast, the concrete shrinks the faster. 7, Shake and smash the way and time. Machinery shake way of smashing than make firm by ramming or tamping way concrete contractivity take little by hand. Shaking should determine according to mechanical performance to smash time , are generally suitable for 55s / time. It is too short, shake and can not smash closely knit , it is insufficient or not even in intensity to form the concrete; It is too long, cause and divide storey, thick aggregate sinks to the ground floor, the upper strata that the detailed aggregate stays, the intensity is not even , the upper strata incident shrink the crack. And shrink the crack caused to temperature, worthy of constructing the reinforcing bar againing can obviously improve the resisting the splitting of concrete , structure of especially thin wall (thick 200cm of wall ). Mix muscle should is it adopt light diameter reinforcing bar (8 |? construct 14 |? ) to have priority , little interval assign (whether @ 10 construct @ 15cm ) on constructing, the whole section is it mix muscle to be rate unsuitable to be lower than 0 to construct. 3%, can generally adopt 0 . 3%~0. 5%.(4), crack that causes out of shape of plinth of the groundBecause foundation vertical to even to subside or horizontal direction displacement, make the structure produce the additional stress, go beyond resisting the ability of drawing of concrete structure, cause the structure to fracture. The even main reason that subside of the foundation is as follows, 1, Reconnoitres the precision and is not enough for , test the materials inaccuratly in geology. Designing, constructing without fully grasping the geological situation, this is the main reason that cause the ground not to subside evenly .Such as hills area or bridge, district of mountain ridge,, hole interval to be too far when reconnoitring, and ground rise and fall big the rock, reconnoitring the report can't fully reflect the real geological situation . 2, The geological difference of the ground is too large. Building it in the bridge of the valley of the ditch of mountain area, geology of the stream place and place on the hillside change larger, even there are weak grounds in the stream, because the soil of the ground does not causes and does not subside evenly with the compressing. 3, The structure loads the difference too big. Under the unanimous terms, when every foundation too heavy to load difference in geological situation, may cause evenly to subside, for example high to fill out soil case shape in the middle part of the culvert than to is it take heavy to load both sides, to subside soon heavy than both sides middle part, case is it might fracture to contain 4, The difference of basic type of structure is great. Unite it in the bridge the samly , mix and use and does not expand the foundation and a foundation with the foundation, or adopt a foundation when a foot-path or a long difference is great at the same time , or adopt the foundation of expanding when basis elevation is widely different at the same time , may cause the ground not to subside evenly too 5, Foundation built by stages. In the newly-built bridge near the foundation of original bridge, if the half a bridge about expressway built by stages, the newly-built bridge loads or the foundation causes the soil of the ground to consolidate again while dealing with, may cause and subside the foundation of original bridge greatly 6, The ground is frozen bloatedly. The ground soil of higher moisture content on terms that lower than zero degree expands because of being icy; Once temperature goes up , the frozen soil is melted, the setting of ground. So the ground is icy or melts causes and does not subside evenly . 7, Bridge foundation put on body, cave with stalactites and stalagmites, activity fault,etc. of coming down at the bad geology, may cause and does not subside evenly . 8, After the bridge is built up , the condition change of original ground . After most natural grounds and artificial grounds are soaked with water, especially usually fill out such soil of special ground as the soil , loess , expanding in the land ,etc., soil body intensity meet water drop, compress out of shape to strengthen. In the soft soil ground , season causes the water table to drop to draw water or arid artificially, the ground soil layer consolidates and sinks again,reduce the buoyancy on the foundation at the same time , shouldering the obstruction of rubing to increase, the foundation is carried on one's shoulder or back and strengthened .Some bridge foundation is it put too shallow to bury, erode , is it dig to wash flood, the foundation might be moved. Ground load change of terms, bridge nearby is it is it abolish square , grit ,etc. in a large amount to put to pile with cave in , landslide ,etc. reason for instance, it is out of shape that the bridge location range soil layer may be compressed again. So, the condition of original ground change while using may cause and does not subside evenly Produce the structure thing of horizontal thrust to arched bridge ,etc., it is the main reason that horizontal displacement crack emerges to destroy the original geological condition when to that it is unreasonable to grasp incompletely , design and construct in the geological situation.桥梁裂缝产生原因浅析近年来，我省交通基础建设得到迅猛发展，各地建立了大量的混凝土桥梁。

本科毕业设计外文文献及译文文献、资料题目：Designing Against Fire Of Building 文献、资料来源：国道数据库文献、资料发表（出版）日期：2008.3.25院（部）：土木工程学院专业：土木工程班级：土木辅修091姓名：xxxx外文文献:Designing Against Fire Of BulidingxxxABSTRACT:This paper considers the design of buildings for fire safety. It is found that fire and the associ- ated effects on buildings is significantly different to other forms of loading such as gravity live loads, wind and earthquakes and their respective effects on the building structure. Fire events are derived from the human activities within buildings or from the malfunction of mechanical and electrical equipment provided within buildings to achieve a serviceable environment. It is therefore possible to directly influence the rate of fire starts within buildings by changing human behaviour, improved maintenance and improved design of mechanical and electrical systems. Furthermore, should a fire develops, it is possible to directly influence the resulting fire severity by the incorporation of fire safety systems such as sprinklers and to provide measures within the building to enable safer egress from the building. The ability to influence the rate of fire starts and the resulting fire severity is unique to the consideration of fire within buildings since other loads such as wind and earthquakes are directly a function of nature. The possible approaches for designing a building for fire safety are presented using an example of a multi-storey building constructed over a railway line. The design of both the transfer structure supporting the building over the railway and the levels above the transfer structure are considered in the context of current regulatory requirements. The principles and assumptions associ- ated with various approaches are discussed.1 INTRODUCTIONOther papers presented in this series consider the design of buildings for gravity loads, wind and earthquakes.The design of buildings against such load effects is to a large extent covered by engineering based standards referenced by the building regulations. This is not the case, to nearly the same extent, in the case of fire. Rather, it is building regulations such as the Building Code of Australia (BCA) that directly specify most of the requirements for fire safety of buildings with reference being made to Standards such as AS3600 or AS4100 for methods for determining the fire resistance of structural elements.The purpose of this paper is to consider the design of buildings for fire safety from an engineering perspective (as is currently done for other loads such as wind or earthquakes), whilst at the same time,putting such approaches in the context of the current regulatory requirements.At the outset,it needs to be noted that designing a building for fire safety is far morethan simply considering the building structure and whether it has sufficient structural adequacy.This is because fires can have a direct influence on occupants via smoke and heat and can grow in size and severity unlike other effects imposed on the building. Notwithstanding these comments, the focus of this paper will be largely on design issues associated with the building structure.Two situations associated with a building are used for the purpose of discussion. The multi-storey office building shown in Figure 1 is supported by a transfer structure that spans over a set of railway tracks. It is assumed that a wide range of rail traffic utilises these tracks including freight and diesel locomotives. The first situation to be considered from a fire safety perspective is the transfer structure.This is termed Situation 1 and the key questions are: what level of fire resistance is required for this transfer structure and how can this be determined? This situation has been chosen since it clearly falls outside the normal regulatory scope of most build- ing regulations. An engineering solution, rather than a prescriptive one is required. The second fire situation (termed Situation 2) corresponds to a fire within the office levels of the building and is covered by building regulations. This situation is chosen because it will enable a discussion of engineering approaches and how these interface with the building regulations–since both engineering and prescriptive solutions are possible.2 UNIQUENESS OF FIRE2.1 IntroductionWind and earthquakes can be considered to b e “natural” phenomena over which designers have no control except perhaps to choose the location of buildings more carefully on the basis of historical records and to design building to resist sufficiently high loads or accelerations for the particular location. Dead and live loads in buildings are the result of gravity. All of these loads are variable and it is possible (although generally unlikely) that the loads may exceed the resistance of the critical structural members resulting in structural failure.The nature and influence of fires in buildings are quite different to those associated with other“loads” to which a building may be subjected to. The essential differences are described in the following sections.2.2 Origin of FireIn most situations (ignoring bush fires), fire originates from human activities within the building or the malfunction of equipment placed within the building to provide a serviceable environment. It follows therefore that it is possible to influence the rate of fire starts by influencing human behaviour, limiting and monitoring human behaviour and improving thedesign of equipment and its maintenance. This is not the case for the usual loads applied to a building.2.3 Ability to InfluenceSince wind and earthquake are directly functions of nature, it is not possible to influence such events to any extent. One has to anticipate them and design accordingly. It may be possible to influence the level of live load in a building by conducting audits and placing restrictions on contents. However, in the case of a fire start, there are many factors that can be brought to bear to influence the ultimate size of the fire and its effect within the building. It is known that occupants within a building will often detect a fire and deal with it before it reaches a sig- nificant size. It is estimated that less than one fire in five (Favre, 1996) results in a call to the fire brigade and for fires reported to the fire brigade, the majority will be limited to the room of fire origin. In oc- cupied spaces, olfactory cues (smell) provide powerful evidence of the presence of even a small fire. The addition of a functional smoke detection system will further improve the likelihood of detection and of action being taken by the occupants.Fire fighting equipment, such as extinguishers and hose reels, is generally provided within buildings for the use of occupants and many organisations provide training for staff in respect of the use of such equipment.The growth of a fire can also be limited by automatic extinguishing systems such as sprinklers, which can be designed to have high levels of effectiveness.Fires can also be limited by the fire brigade depending on the size and location of the fire at the time of arrival. 2.4 Effects of FireThe structural elements in the vicinity of the fire will experience the effects of heat. The temperatures within the structural elements will increase with time of exposure to the fire, the rate of temperature rise being dictated by the thermal resistance of the structural element and the severity of the fire. The increase in temperatures within a member will result in both thermal expansion and,eventually,a reduction in the structural resistance of the member. Differential thermal expansion will lead to bowing of a member. Significant axial expansion will be accommodated in steel members by either overall or local buckling or yielding of local- ised regions. These effects will be detrimental for columns but for beams forming part of a floor system may assist in the development of other load resisting mechanisms (see Section 4.3.5).With the exception of the development of forces due to restraint of thermal expansion, fire does not impose loads on the structure but rather reduces stiffness and strength. Such effects are not instantaneous but are a function of time and this is different to the effects of loads such as earthquake and wind that are more or less instantaneous.Heating effects associated with a fire will not be significant or the rate of loss of capacity will be slowed if:(a) the fire is extinguished (e.g. an effective sprinkler system)(b) the fire is of insufficient severity – insufficient fuel, and/or(c)the structural elements have sufficient thermal mass and/or insulation to slow the rise in internal temperatureFire protection measures such as providing sufficient axis distance and dimensions for concrete elements, and sufficient insulation thickness for steel elements are examples of (c). These are illustrated in Figure 2.The two situations described in the introduction are now considered.3 FIRE WITHIN BUILDINGS3.1 Fire Safety ConsiderationsThe implications of fire within the occupied parts of the office building (Figure 1) (Situation 2) are now considered. Fire statistics for office buildings show that about one fatality is expected in an office building for every 1000 fires reported to the fire brigade. This is an order of magnitude less than the fatality rate associated with apartment buildings. More than two thirds of fires occur during occupied hours and this is due to the greater human activity and the greater use of services within the building. It is twice as likely that a fire that commences out of normal working hours will extend beyond the enclosure of fire origin.A relatively small fire can generate large quantities of smoke within the floor of fire origin. If the floor is of open-plan construction with few partitions, the presence of a fire during normal occupied hours is almost certain to be detected through the observation of smoke on the floor. The presence of full height partitions across the floor will slow the spread of smoke and possibly also the speed at which the occupants detect the fire. Any measures aimed at improving housekeeping, fire awareness and fire response will be beneficial in reducing thelikelihood of major fires during occupied hours.For multi-storey buildings, smoke detection systems and alarms are often provided to give “automatic” detection and warning to the occupants. An alarm signal is also transmitted to the fire brigade.Should the fire not be able to be controlled by the occupants on the fire floor, they will need to leave the floor of fire origin via the stairs. Stair enclosures may be designed to be fire-resistant but this may not be sufficient to keep the smoke out of the stairs. Many buildings incorporate stair pressurisation systems whereby positive airflow is introduced into the stairs upon detection of smoke within the building. However, this increases the forces required to open the stair doors and makes it increasingly difficult to access the stairs. It is quite likely that excessive door opening forces will exist(Fazio et al,2006)From a fire perspective, it is common to consider that a building consists of enclosures formed by the presence of walls and floors.An enclosure that has sufficiently fire-resistant boundaries (i.e. walls and floors) is considered to constitute a fire compartment and to be capable of limiting the spread of fire to an adjacent compartment. However, the ability of such boundaries to restrict the spread of fire can be severely limited by the need to provide natural lighting (windows)and access openings between the adjacent compartments (doors and stairs). Fire spread via the external openings (windows) is a distinct possibility given a fully developed fire. Limit- ing the window sizes and geometry can reduce but not eliminate the possibility of vertical fire spread.By far the most effective measure in limiting fire spread, other than the presence of occupants, is an effective sprinkler system that delivers water to a growing fire rapidly reducing the heat being generated and virtually extinguishing it.3.2 Estimating Fire SeverityIn the absence of measures to extinguish developing fires, or should such systems fail; severe fires can develop within buildings.In fire en gineering literature, the term “fire load” refers to the quantity of combustibles within an enclosure and not the loads (forces) applied to the structure during a fire. Similarly, fire load density refers to the quantity of fuel per unit area. It is normally expressed in terms of MJ/m2 or kg/m2 of wood equivalent. Surveys of combustibles for various occupancies (i.e offices, retail, hospitals, warehouses, etc)have been undertaken and a good summary of the available data is given in FCRC (1999). As would be expected, the fire load density is highly variable. Publications such as the International Fire Engineering Guidelines (2005) give fire load data in terms of the mean and 80th percentile.The latter level of fire load density is sometimes taken asthe characteristic fire load density and is sometimes taken as being distributed according to a Gumbel distribution (Schleich et al, 1999).The rate at which heat is released within an enclosure is termed the heat release rate (HRR) and normally expressed in megawatts (MW). The application of sufficient heat to a combustible material results in the generation of gases some of which are combustible. This process is called pyrolisation.Upon coming into contact with sufficient oxygen these gases ignite generating heat. The rate of burning(and therefore of heat generation) is therefore dependent on the flow of air to the gases generated by the pyrolising fuel.This flow is influenced by the shape of the enclosure (aspect ratio), and the position and size of any potential openings. It is found from experiments with single openings in approximately cubic enclosures that the rate of burning is directly proportional to A h where A is the area of the opening and h is the opening height. It is known that for deep enclosures with single openings that burning will occur initially closest to the opening moving back into the enclosure once the fuel closest to the opening is consumed (Thomas et al, 2005). Significant temperature variations throughout such enclosures can be expected.The use of the word ‘opening’ in relation to real building enclosures refers to any openings present around the walls including doors that are left open and any windows containing non fire-resistant glass.It is presumed that such glass breaks in the event of development of a significant fire. If the windows could be prevented from breaking and other sources of air to the enclosure limited, then the fire would be prevented from becoming a severe fire.Various methods have been developed for determining the potential severity of a fire within an enclosure.These are described in SFPE (2004). The predictions of these methods are variable and are mostly based on estimating a representative heat release rate (HRR) and the proportion of total fuel ςlikely to be consumed during the primary burning stage (Figure 4). Further studies of enclosure fires are required to assist with the development of improved models, as the behaviour is very complex.3.3 Role of the Building StructureIf the design objectives are to provide an adequate level of safety for the occupants and protection of adjacent properties from damage, then the structural adequacy of the building in fire need only be sufficient to allow the occupants to exit the building and for the building to ultimately deform in a way that does not lead to damage or fire spread to a building located on an adjacent site.These objectives are those associated with most building regulations includingthe Building Code of Australia (BCA). There could be other objectives including protection of the building against significant damage. In considering these various objectives, the following should be taken into account when considering the fire resistance of the building structure.3.3.1 Non-Structural ConsequencesSince fire can produce smoke and flame, it is important to ask whether these outcomes will threaten life safety within other parts of the building before the building is compromised by a loss of structural adequacy? Is search and rescue by the fire brigade not feasible given the likely extent of smoke? Will the loss of use of the building due to a severe fire result in major property and income loss? If the answer to these questions is in the affirmative, then it may be necessary to minimise the occurrence of a significant fire rather than simply assuming that the building structure needs to be designed for high levels of fire resistance. A low-rise shopping centre with levels interconnected by large voids is an example of such a situation.3.3.2 Other Fire Safety SystemsThe presence of other systems (e.g. sprinklers) within the building to minimise the occurrence of a serious fire can greatly reduce the need for the structural elements to have high levels of fire resistance. In this regard, the uncertainties of all fire-safety systems need to be considered. Irrespective of whether the fire safety system is the sprinkler system, stair pressurisation, compartmentation or the system giving the structure a fire-resistance level (e.g. concrete cover), there is an uncertainty of performance. Uncertainty data is available for sprinkler systems(because it is relatively easy to collect) but is not readily available for the other fire safety systems. This sometimes results in the designers and building regulators considering that only sprinkler systems are subject to uncertainty. In reality, it would appear that sprinklers systems have a high level of performance and can be designed to have very high levels of reliability.3.3.3 Height of BuildingIt takes longer for a tall building to be evacuated than a short building and therefore the structure of a tall building may need to have a higher level of fire resistance. The implications of collapse of tall buildings on adjacent properties are also greater than for buildings of only several storeys.3.3.4 Limited Extent of BurningIf the likely extent of burning is small in comparison with the plan area of the building, then the fire cannot have a significant impact on the overall stability of the building structure. Examples of situations where this is the case are open-deck carparks and very large area building such as shopping complexes where the fire-effected part is likely to be small in relation to area of the building floor plan.3.3.5 Behaviour of Floor ElementsThe effect of real fires on composite and concrete floors continues to be a subject of much research.Experimental testing at Cardington demonstrated that when parts of a composite floor are subject to heating, large displacement behaviour can develop that greatly assists the load carrying capacity of the floor beyond that which would predicted by considering only the behaviour of the beams and slabs in isolation.These situations have been analysed by both yield line methods that take into account the effects of membrane forces (Bailey, 2004) and finite element techniques. In essence, the methods illustrate that it is not necessary to insulate all structural steel elements in a composite floor to achieve high levels of fire resistance.This work also demonstrated that exposure of a composite floor having unprotected steel beams, to a localised fire, will not result in failure of the floor.A similar real fire test on a multistory reinforced concrete building demonstrated that the real structural behaviour in fire was significantly different to that expected using small displacement theory as for normal tempera- ture design (Bailey, 2002) with the performance being superior than that predicted by considering isolated member behaviour.3.4 Prescriptive Approach to DesignThe building regulations of most countries provide prescriptive requirements for the design of buildings for fire.These requirements are generally not subject to interpretation and compliance with them makes for simpler design approval–although not necessarily the most cost-effective designs.These provisions are often termed deemed-to-satisfy (DTS) provisions. All aspects of designing buildings for fire safety are covered–the provision of emergency exits, spacings between buildings, occupant fire fighting measures, detection and alarms, measures for automatic fire suppression, air and smoke handling requirements and last, but not least, requirements for compartmentation and fire resistance levels for structural members. However, there is little evidence that the requirements have been developed from a systematic evaluation of fire safety. Rather it would appear that many of the requirements have been added one to another to deal with another fire incident or to incorporate a new form of technology. There does not appear to have been any real attempt to determine which provision have the most significant influence on fire safety and whether some of the former provisions could be modified.The FRL requirements specified in the DTS provisions are traditionally considered to result in member resistances that will only rarely experience failure in the event of a fire.This is why it is acceptable to use the above arbitrary point in time load combination for assessing members in fire. There have been attempts to evaluate the various deemed-to-satisfy provisions (particularly the fire- resistance requirements)from a fire-engineering perspective taking intoaccount the possible variations in enclosure geometry, opening sizes and fire load (see FCRC, 1999).One of the outcomes of this evaluation was the recognition that deemed-to- satisfy provisions necessarily cover the broad range of buildings and thus must, on average, be quite onerous because of the magnitude of the above variations.It should be noted that the DTS provisions assume that compartmentation works and that fire is limited to a single compartment. This means that fire is normally only considered to exist at one level. Thus floors are assumed to be heated from below and columns only over one storey height.3.5 Performance-Based DesignAn approach that offers substantial benefits for individual buildings is the move towards performance-based regulations. This is permitted by regulations such as the BCA which state that a designer must demonstrate that the particular building will achieve the relevant performance requirements. The prescriptive provisions (i.e. the DTS provisions) are presumed to achieve these requirements. It is necessary to show that any building that does not conform to the DTS provisions will achieve the performance requirements.But what are the performance requirements? Most often the specified performance is simply a set of performance statements (such as with the Building Code of Australia)with no quantitative level given. Therefore, although these statements remind the designer of the key elements of design, they do not, in themselves, provide any measure against which to determine whether the design is adequately safe.Possible acceptance criteria are now considered.3.5.1 Acceptance CriteriaSome guidance as to the basis for acceptable designs is given in regulations such as the BCA. These and other possible bases are now considered in principle.(i)compare the levels of safety (with respect to achieving each of the design objectives) of the proposed alternative solution with those asso- ciated with a corresponding DTS solution for the building.This comparison may be done on either a qualitative or qualitative risk basis or perhaps a combination. In this case, the basis for comparison is an acceptable DTS solution. Such an approach requires a “holistic” approach to safety whereby all aspects relevant to safety, including the structure, are considered. This is, by far, the most common basis for acceptance.(ii)undertake a probabilistic risk assessment and show that the risk associated with the proposed design is less than that associated with common societal activities such as using pub lic transport. Undertaking a full probabilistic risk assessment can be very difficult for all but the simplest situations.Assuming that such an assessment is undertaken it will be necessary for the stakeholders to accept the nominated level of acceptable risk. Again, this requires a “holistic”approach to fire safety.(iii) a design is presented where it is demonstrated that all reasonable measures have been adopted to manage the risks and that any possible measures that have not been adopted will have negligible effect on the risk of not achieving the design objectives.(iv) as far as the building structure is concerned,benchmark the acceptable probability of failure in fire against that for normal temperature design. This is similar to the approach used when considering Building Situation 1 but only considers the building structure and not the effects of flame or smoke spread. It is not a holistic approach to fire safety.Finally, the questions of arson and terrorism must be considered. Deliberate acts of fire initiation range from relatively minor incidents to acts of mass destruction.Acts of arson are well within the accepted range of fire events experienced by build- ings(e.g. 8% of fire starts in offices are deemed "suspicious"). The simplest act is to use a small heat source to start a fire. The resulting fire will develop slowly in one location within the building and will most probably be controlled by the various fire- safety systems within the building. The outcome is likely to be the same even if an accelerant is used to assist fire spread.An important illustration of this occurred during the race riots in Los Angeles in 1992 (Hart 1992) when fires were started in many buildings often at multiple locations. In the case of buildings with sprinkler systems,the damage was limited and the fires significantly controlled.Although the intent was to destroy the buildings,the fire-safety systems were able to limit the resulting fires. Security measures are provided with systems such as sprinkler systems and include:- locking of valves- anti-tamper monitoring- location of valves in secure locationsFurthermore, access to significant buildings is often restricted by security measures.The very fact that the above steps have been taken demonstrates that acts of destruction within buildings are considered although most acts of arson do not involve any attempt to disable the fire-safety systems.At the one end of the spectrum is "simple" arson and at the other end, extremely rare acts where attempts are made to destroy the fire-safety systems along with substantial parts of the building.This can be only achieved through massive impact or the use of explosives. The latter may be achieved through explosives being introduced into the building or from outside by missile attack.The former could result from missile attack or from the collision of a large aircraft. The greater the destructiveness of the act,the greater the means and knowledge required. Conversely, the more extreme the act, the less confidence there can be in designing against suchan act. This is because the more extreme the event, the harder it is to predict precisely and the less understood will be its effects. The important point to recognise is that if sufficient means can be assembled, then it will always be possible to overcome a particular building design.Thus these acts are completely different to the other loadings to which a building is subjected such as wind,earthquake and gravity loading. This is because such acts of destruction are the work of intelligent beings and take into account the characteristics of the target.Should high-rise buildings be designed for given terrorist activities,then terrorists will simply use greater means to achieve the end result.For example, if buildings were designed to resist the impact effects from a certain size aircraft, then the use of a larger aircraft or more than one aircraft could still achieve destruction of the building. An appropriate strategy is therefore to minimise the likelihood of means of mass destruction getting into the hands of persons intent on such acts. This is not an engineering solution associated with the building structure.It should not be assumed that structural solutions are always the most appropriate, or indeed, possible.In the same way, aircrafts are not designed to survive a major fire or a crash landing but steps are taken to minimise the likelihood of either occurrence.The mobilization of large quantities of fire load (the normal combustibles on the floors) simultaneously on numerous levels throughout a building is well outside fire situations envisaged by current fire test standards and prescriptive regulations. Risk management measures to avoid such a possibility must be considered.4 CONCLUSIONSFire differs significantly from other “loads” such as wind, live load and earthquakes i n respect of its origin and its effects.Due to the fact that fire originates from human activities or equipment installed within buildings, it is possible to directly influence the potential effects on the building by reducing the rate of fire starts and providing measures to directly limit fire severity.The design of buildings for fire safety is mostly achieved by following the prescriptive requirements of building codes such as the BCA. For situations that fall outside of the scope of such regulations, or where proposed designs are not in accordance with the prescriptive requirements, it is possible to undertake performance-based fire engineering designs.However, there are no design codes or standards or detailed methodologies available for undertaking such designs.Building regulations require that such alternative designs satisfy performance requirements and give some guidance as to the basis for acceptance of these designs (i.e. acceptance criteria).This paper presents a number of possible acceptance criteria, all of which use the measure of risk level as the basis for comparison.Strictly, when considering the risks。

土木工程建筑外文翻译外文文献高层建筑的消防安全设计Fire Safety Design for High-rise BuildingsKeywords: fire safety, high-rise buildings, means of escape, fire resistant materials, fire detection and alarm systems, fire suppression systems, fire risk assessment, emergency plans1. Introduction2. Means of Escape3. Fire Resistant Materials4. Fire Detection and Alarm SystemsEarly detection of a fire is crucial to allow for the safe evacuation of occupants. High-rise buildings should be equipped with fire detection and alarm systems, including smoke detectors, heat detectors, and manual call points. These systems should be interconnected and monitored to ensure prompt notification of a fire.5. Fire Suppression Systems6. Fire Risk AssessmentBefore occupancy, a fire risk assessment should be conducted to identify potential fire hazards and ensure appropriate fire safety measures are in place. This assessment should considerthe building's use, occupant load, and fire resistance ofconstruction materials. Regular fire risk assessments shouldalso be conducted to address any changes in building use or occupancy.7. Emergency PlansHigh-rise buildings should have well-defined emergency plans that outline the actions to be taken in the event of a fire. These plans should include procedures for evacuating occupants, contacting emergency services, and isolating fire-affected areas. Regular drills and training sessions should be conducted to familiarize occupants with the emergency procedures.8. ConclusionFire safety design is critical in high-rise buildings to protect the lives of occupants and minimize property damage. Designers and engineers should consider means of escape, fire resistant materials, fire detection and alarm systems, fire suppression systems, fire risk assessments, and emergency plans when designing a high-rise building. By implementing these measures effectively, the risk of fire-related incidents can be significantly reduced.。

土木工程专业毕业设计外文文献翻译2篇XXXXXXXXX学院学士学位毕业设计（论文）英语翻译课题名称英语翻译学号学生专业、年级所在院系指导教师选题时间Fundamental Assumptions for Reinforced ConcreteBehaviorThe chief task of the structural engineer is the design of structures. Design is the determination of the general shape and all specific dimensions of a particular structure so that it will perform the function for which it is created and will safely withstand the influences that will act on it throughout useful life. These influences are primarily the loads and other forces to which it will be subjected, as well as other detrimental agents, such as temperature fluctuations, foundation settlements, and corrosive influences, Structural mechanics is one of the main tools in this process of design. As here understood, it is the body of scientific knowledge that permits one to predict with a good degree of certainly how a structure of give shape and dimensions will behave when acted upon by known forces or other mechanical influences. The chief items of behavior that are of practical interest are (1) the strength of the structure, i. e. , that magnitude of loads of a give distribution which will cause the structure to fail, and (2) the deformations, such as deflections and extent of cracking, that the structure will undergo when loaded underservice condition.The fundamental propositions on which the mechanics of reinforced concrete is based are as follows:1.The internal forces, such as bending moments, shear forces, and normal andshear stresses, at any section of a member are in equilibrium with the effect of the external loads at that section. This proposition is not an assumption but a fact, because any body or any portion thereof can be at rest only if all forces acting on it are in equilibrium.2.The strain in an embedded reinforcing bar is the same as that of thesurrounding concrete. Expressed differently, it is assumed that perfect bonding exists between concrete and steel at the interface, so that no slip can occur between the two materials. Hence, as the one deforms, so must the other. With modern deformed bars, a high degree of mechanical interlocking is provided in addition to the natural surface adhesion, so this assumption is very close to correct.3.Cross sections that were plane prior to loading continue to be plan in themember under load. Accurate measurements have shown that when a reinforced concrete member is loaded close to failure, this assumption is not absolutely accurate. However, the deviations are usually minor.4.In view of the fact the tensile strength of concrete is only a small fraction ofits compressive strength; the concrete in that part of a member which is in tension is usually cracked. While these cracks, in well-designed members, are generally so sorrow as to behardly visible, they evidently render the cracked concrete incapable of resisting tension stress whatever. This assumption is evidently a simplification of the actual situation because, in fact, concrete prior to cracking, as well as the concrete located between cracks, does resist tension stresses of small magnitude. Later in discussions of the resistance of reinforced concrete beams to shear, it will become apparent that under certain conditions this particular assumption is dispensed with and advantage is taken of the modest tensile strength that concrete can develop.5.The theory is based on the actual stress-strain relation ships and strengthproperties of the two constituent materials or some reasonable equivalent simplifications thereof. The fact that novelistic behavior is reflected in modern theory, that concrete is assumed to be ineffective in tension, and that the joint action of the two materials is taken into consideration results in analytical methods which are considerably more complex and also more challenging, than those that are adequate for members made of a single, substantially elastic material.These five assumptions permit one to predict by calculation the performance of reinforced concrete members only for some simple situations. Actually, the joint action of two materials as dissimilar and complicated as concrete and steel is so complex that it has not yet lent itself to purely analytical treatment. For this reason, methods of design and analysis, while using these assumptions, are very largely based on the results of extensive and continuing experimental research. They are modified and improved as additional test evidence becomes available.钢筋混凝土的基本假设作为结构工程师的主要任务是结构设计。

毕业设计（论文）外文翻译题目西北物流中心2号楼设计专业土木工程班级土木074学生指导教师二零一零年Low-coherence deformation sensors for themonitoring of civil-engineering structuresD. Inaudi a, A. Elamari b, L. Pflug a, N. Gisin b, J. Breguet b, S. Vurpillot a “IMAC, Laboratory of Stress Analysis, Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland ‘GAP, Group of Applied Physics -Optical Seciion, Geneva University CH-1205 Geneva, SwitzerlandRcccivcd 25 January 1993; in revised form 8 March 1994; accepted 25 March 1994 AbstractAn optical-fiber deformation sensor with a resolution of 10 pm and an operational range of 60 mm has been realized. The system is based on low-coherence interferometry instandard single-mode telecommunication fibers. It allows the monitoring of large structures over several months without noticeable drift. No continuous measurement is needed and the system is insensitive to variations of the fiber losses. This technique has been applied to the monitoring of a 20 m X5 m X0.5 m, 120 ton concrete slab over six months. It is possible to measure the shrinkage of concrete and its elastic coefficient during pre-straining, giving reproducible results in good agreement with theoretical calculations and measurements performed on small concrete samples. This paper describes the optical arrangement and the procedures used to install optical fibers in concrete.Keywor&: Ikformation sensors; Civil-engineering structures1. IntroductionBoth the security of civil-engineering works and the law require a periodic monitoring of structures. The methods used for this purpose, such as triangulation, water levels or vibrating strings, are often of tedious application and require one or many specialized operators. This complexity and the resulting costs limit the frequency of the measurements. Furthermore, the spatial resolution is often poor and the observation is usually restricted to the surface of the object. There is thus a real demand for a tool allowing an internal, automatic and permanent monitoring of structures with high accuracy and stability over periods typically of the order of 100 years for bridges. In this framework, fiber-optic smart structures (i.e., structures with self-testing capabilities) are gaining in importance in many fields including aeronautics and composite material monitoring. This technology can be applied in civilengineering and in particular for the short- and long-time observation of large structures such as bridges, tall building frames, dams, tunnels, roads, airport runways, domes, pre-stressing and anchorage cables. The monitoring of such structures requires the development of a measuring technique with high accuracy,stability and reliability over long periods. It has to beindependent of variations in the fiber losses and adapted to the adverse environment of a building site. To reduce the cost of the instrumentation, it is furthermore desirable to use the same portable reading unit for the monitoring of multiple structures. We describe here asystem based on low-coherence interferometry responding to all these requirements.2. Experimental arrangementThe measuring technique relies on an array of standard telecommunication optical fibers in mechanical contact with concrete. Any deformation of the host structure results jn a change in the optical length of he fibers. Each sensor line consists of two single-mode ibers: one measurement fiber in mechanical contact with the structure (glued or cemented) and a reference iber placed loose near the first one (in a pipe) in order to be at the same temperature. Since the measurement technique monitors the length difference beween these two fibers, only the mechanical deformation will have an effect on the results while all other perurbations, such as thermally induced changes in the refractive index of the fibers,will affect the two in an identical way and cancel each another out. To measure the optical path difference between the two fibers, a low-coherence double interferometer in tandem configuration has been used (Fig. 1) [l]. The source is an LED (light-emitting diode) working around 1.3 pm with a coherence length L, of 30 pm and a rated power of 200 pW. The radiation is launched into a single-mode fiber and then directed toward the measurement and the reference fibers by means of a 50:50 single-mode directional coupler. At the ends of the fibers two mirrors reflect the light back to the coupler, where the beams arc recombined with a relative delay due to the length difference AL, between the fibers, and then directed towards the second (reference) interferometer. The reference interferometer is of Michelson type with one of the arms ended by a mobile mirror mounted on a micromctric displacement table with a resolution of 0.1 pm and an operating range of 50 mm. It allows the introduction of an exactly known path difFcrence AL, between its two arms. This fiber interferometer is portable and needs no optical adjustment after transportation. It has been developed by the GAP with the support of the Swiss PTT for optical cable testing [2].The intensity at the output of the reference inter- ferometer is measured with a pig-tail photodiode and is then given by [3]where zz,,r is the effective refractive index of the fiber, zzg the group refractive index (about 1% higher than nefr in silica), A, the central vacuum wavelength of the light, zi,, the autocorrelation function taking the spectral characteristics of the emission into account and AL the physical path difference between the two interfering paths. Further similar interference terms appear in Eq.(1) in the special cases when AL, <L, or AL, < L,. When the optical path difference between the arms in the reference interferometer corresponds to the one induced by the two fibers installed in the structure (within the coherence length of the source), interference fringes appear. Scanning AL, with the mirror of the reference interferometer it is possible to obtain AL = 0either with AL, = AL, or with AL, = -AL,, and thus two interference fringe packets as described by Eq. (1). The mirror position corresponding to AL, = 0 also produces an interference and is used as a reference. These three fringe packets arc detected by means of a lock-in amplifier synchronized with the mirror displacements. The mirror displacements and the digitalization of the lock-in output are carried out by means of a portable personal computer. Since the reference signal is gcnerated separately and does not have a constant phase relation to the interference signal, only the envelope of the demodulated signal has a physical meaning and corresponds to the envelope of the fringe pattern. A lock-in plot showing the three typical peaks is shown in Fig. 2. Each peak has a width of about 30 pm. The calculation of its center of gravity determines its position with a precision better than 10 pm. This precision is the limiting factor of the whole measurement technique. Since AL, is known with micrometer precision, it is possible to follow AL, with the same precision.Fig. 1. Experimental setup of the low-coherence double Michelson interferomctcr. D. Innudi et al. 1 Semors andFig. 2. Typical fringe cnvclope as a function of the mirror position. The distance between the central and the lateral peaks corresponds to the length difference between the measurement and the reference fibers mounted in the table. Any change in the length of the structure results in a change in the position of these peaks. Any change in the losses of the fibers will result in a change of the height of the peaks. The central peak is fixed and used as a reference.The path difference AL, is proportional to the de-formation of the structure AL, with the relation between the two given by [4]where p is Poisson’s ratio and pij is the strain optic tensor (Pockcl’s coefhcients). The coefficient 5 takes into account the variation of the effective index neff in a fiber under strain.A degradation of one or both fibers (due to aging, for example) will result in a lower visibilityof the fringes but will not affect its position. The information about the deformation of the structure is encoded in the coherence properties of light and not in its intensity as in the majority of the sensors applied to date in civil-engineering structures, mostly based on microbend losses and/or optical time-domain reflectometry (OTDR) techniques. Interference peaks resulting from reflections as low as -30 dB of the source power can be detected by our system without phase modulators. By modulating the phase in one of the four arms of the two interferometers, one can increase the dynamic range of the device to more than 100 dB [5].Even if the polarization dispersion and bend-induced birefringence in the sensing fibers could reduce the visibility of the interference fringes or even split the fringe packets, none of those effects was observed in our experiment. No adjustment of polarization between the reference and the sensing arm was then necessary. A good mechanical contact between the measurement fiber and the structure under test is fundamental. In this study a number of installation procedures have been tested and optimized for the different measurements (shrinkage, elasticity modulus, etc.). The mounting techniques can be divided into two main categories: full-length coupling and local coupling.During our tests five out of six optical fiber pairs with a 0.9 mm nylon coating, being mounted on the external face of a 20 m long plastic pipe and protected only with thin rubber bands (see Fig. 3(a)), survived the concreting process. During the setting process the concrete envelops the fiber and realizes the desired mechanical contact. Those fibers showed a minor increase in the scattering losses and the appearance of small parasite peaks. The measurements on those fibers were consistent with the results obtained with other installation techniques (see below). It seems that for full-length coupling the nylon coating transmits the structure deformations (extension and shortening) entirely to the fiber core. This installation technique is very promising when compared to the usual procedure, consisting of a pipe protecting the fibers during the pouring of concrete and being removed before the setting process begins. This second method seemsmore adapted to small samples than to full-scale structures. Eleven otherfiber pairs were glued at the two ends of the table after removing locally the protective coating layers of the fibers (see Fig. 3(b)). The silica fiber was ftxed with epoxy glue to a metallic plate mounted on the end facesof the concrete structure. The gluing length was about 20 mm. Apre-strain (between 0.1 and 0.4%) has been given to those fibers during the gluing process to keep them under tension and allow the measurement of both expansion and shrinkage of the structure. This type of local coupling proved to be the most reliable, but was not adapted to following thedeformation during the pre-stressing of the table because of the important surface deformations occurring during this operation. The problem has been overcome by gluing other fibers inside the pipes at about two meters from the surfaces, i.e., far from the force insertion region (see Fig. 3(c)).Fig. 3. Schematic representation of three of the installation techniques used:(a) direct concreting of the measurement fiber mounted on a plastic pipe; (b) fiber glued at the table surface; (c) fiber glued inside the pipe at 2m from the pipe ends.Fig. 4. Top and side views of the concrete table measured in the experiment and position of the sensing-fiber pairs A, B, C and D. Fibers A, B and C arc glued at the surface of the structure, while fiber D is glued inside a pipe, 2 m away from the surface of the slab. Twelve more fihcr pairs were installed, but are not shown for simplicity.To study the possible effect of creep in strained fibers [6], one fiber has been mounted on a mechanical support that allows the fiber to be tightened only at the time of the measurement. No difference between this fiberand those permanently strained has been observed over a period of six months, confirming the assumption that no creep occurs for fiber strains below 1%. Since the scanning range of the mirror is 5 mm, it was easy to cleave the 20 m long fibers within this margin. The Fresnel reflection of the cleaved fibers combined with the high dynamic of the system allow a measurement of AL,,. This value of AL, can than be used to correct the cutting and obtain pairs with length differences below 1 mm. Two ferrules were then installed on the fiber ends and mounted in front of a polished inox surface. Chemical silver deposition was also used to produce mirrors on the cleaved fiber ends.Fig. 6. Comparison between the measurements performed on the structure by optical fibers and the ones performed on 360 mm and 500 mm samples in a mechanical micrometer comparator. The measurement on the samples was possible only during the first two months.3. ResultsSeveral long- and short-term measurements have been carried on a 20 m x 5 m x 0.5 m, 120 ton concrete slab intended to be used as a vibration-isolated base for optical analysis (in particular by holographic and speckle interferometry) of large structures [7].This structure has been concreted indoors, allowing controlled environmcntal conditions and known concrete composition to be achieved. Samples have been prepared with the same material composition and are under permanent test for their mechanical properties (resistance, shrinkage and elastic coefficient). This allows a direct comparison between the results on the full-scale structure and the samples. The table has been pre-strained 23 days after concreting in both length and width. It was possible at this time to measure the elastic coefficient of the material in full scale. Fig. 4 shows a schematic representation of the table and the position of the fibers referred to in the experimental results. At the time of writing, the table has been under test for six months. Over this period the shrinkage in the longitudinal direction (i.e., over 20 m) has been about 6 mm. We show in Fig. 5 the results of the measurements for three (glued) fibers over 175 days. The table has a T profile (Fig. 4). It is evident from Fig. 5 that thefibers mounted near the borders of the table, i.e., were the thickness is smaller, registered a larger shrinkage, as expected according to the concrete theory. Adjacentfibers give consistent results independently of the installation technique. No difference has been noticed between the fibers under permanent tension and those loosened between the measurements, suggesting that no creep of glass fibers occurred. The shrinkage measured with the fiber system has been compared during the first two months with the results obtained with a mechanical comparator mounted on two samples of 360 mm and 500 mm, respectively.The observed deformations have been scaled to 20m and are compared in Fig.6 to the results obtained with fibers B and C. Very good agreement is found between the two measurements. A theoretical comparison between the experimentalresults and the Swiss civil engineering standards has also been carried out. The experimental data and the standards are in agreement within f 10%. A more accurate simulation including the physico-chemical properties of the concrete used is under development. The table was pre-stressed 23 days after concreting. The five steel cables running over the length of the table and the forty cables running over its width were stretched with a force of 185 kN (18.5 Tons) each. The fibers glued to the surface and those in direct contact with concrete over the whole length measured an expansion of the table instead of the expected shrinkage. This is due to the important surface deformations occurring near the force-insertion points, i.e., near the pre-stress heads that were placed near the fiber ends. Fiber D glued inside the plastic pipe at 2m from each endwas not subject to these local effects and measured a shortening of 0.23 mm. The theoretical calculation based on an elastic coefficient of 30 kN/mm2gives a shortening of 0.28mm at the borders and 0.19 mm at the center of the table. Since fiber D was placed in an intermediate position, the experimental value can be considered to be in good agreement with the theory.4. ConclusionsA new deformation sensor adapted to the monitoring of civil-engineering structures has been proposed. it is based on low-coherence interferometry in standard lowcost telecommunication fibers. The resolution of the measurements is 10 pm, the operational range is 60mm and the stability has been tested over six months without noticeable drift. The reading unit is compact and portable, needing no optical alignment before the measurements. It is controlled by a portable personal computer, which is also responsible for the data trcatment. The same reading unit can be used to monitor multiple fiber lines by simple manual unplugging. This technique is furthermore practically insensitive to increased losses due to degradation of the fibers. A test study has been carried out on a 20m ~5m X 0.5m concrete slab, giving consistent results when compared to other measurement techniques based on samples or to concrete theories. It was possible to follow concrete shrinkage over six months (the cxper- iment will continue for about five years) and to measure the elastic coefficient on the full-scale structure. Different fiber-installation techniques adapted to the measurement of various parameters have been tested in building-site conditions. This technique appears very promising for the mon-itoring of civil-engineering structures such as bridges, dams and tunnels, allowing internal, automatic and permanent monitoring with high precision and stability over long periods.AcknowledgmentsThe authors are indebted to R. Passy and R. Delez for their assistance, encouragement and helpful dis-cussion. We acknowledge the IMM Institute in Lugano (Switzerland) for placing the table at our disposal and for the measurements carried out on concrete samples. We are grateful to Dr M. Pedretti and Ing R. Passera for their personal engagement in the project. We also thank Cabloptic in Cortaillod (Switzerland) for sup-plying all the optical fibers used in the experiment. This research has been performed with the financial support of CERS (Commission pour 1’Encouragement de la Recherche Scientifique).References[1] A.Koch and R.Ulrich,Fiber optic displacement sensor with 0.02mm resolutionbuy white-light interferometry,sensors and actuators A,25-27(1991)201-207[2]N.Gisin,J.-P.Von der weid and J.-P.Pellaux,Polarization mode dispersion ofshort and long single-mode fibers,J.Lightwave technol,9(1991)821-827.[3] A.S.Gergcs,F.Farahi,T.P.Newson,J.D.C.Jones and D.A.Jackson, Fiber-opticinterferometric sensors using low coherence source:dynamic range enhancement,Int. J.Op-toelectron,3(1988)311-322.[4] C.D.Butter and G.B.Hacker, Fiber optics strain gauge,Appl.Opt,17(1978)2867-2869.[5]H.H.Gilger,G.Bodmer and Ch.Zimmer, Optical coherance domain retlectometry asa test method of integrated optics devices,Proc.2nd Opt. Fibre Meas. Conf:OFMC 93, Turin, Ztuly, Z993, pp.143-146.[6]J.-P.Jaguin and A.Zaganiaris,La mecanique de rupture appliquee aux fibresoptiques, Verres Refract, 34 (Jul-Aout)(1980).[7]L.Pflug and M.Pedretti, Construction of a loo-tonnes holographictable,ZS&TISPIE Znt.Symp. Electronic Imaging, SanJose,CA,USA,1993,pp.50-54.传感器和执行器 A 44（1994）12.5-130用低变形传感器监测民用工程结构变形的一致性D.Inaudi a, A.Elamari b, L.Pflug b, N.Gisin b, J.Breguet b, S.Vurpillot aa IMAC、实验室的应力分析,瑞士联邦理工学院,CH-1015瑞士洛桑b GAP,群应用物理-光学部分,日内瓦大学，CH-1205瑞士日内瓦举行1993年1月25日实验;1994年3月8日修订,1994年3月25日发表文摘一个光纤变形的分辨率的传感器,10µm和运行范围的60毫米已经实现了。

英文原文：Rehabilitation of rectangular simply supported RC beams with shear deficiencies using CFRP compositesAhmed Khalifa a,＊, Antonio Nanni ba Department of Structural Engineering，University of Alexandria，Alexandria 21544，Egyptb Department of Civil Engineering，University of Missouri at Rolla，Rolla，MO 65409，USAReceived 28 April 1999；received in revised form 30 October 2001；accepted 10 January 2002AbstractThe present study examines the shear performance and modes of failure of rectangular simply supported reinforced concrete(RC) beams designed with shear deficiencies。

These members were strengthened with externally bonded carbon fiber reinforced polymer （CFRP）sheets and evaluated in the laboratory. The experimental program consisted of twelve full—scale RC beams tested to fail in shear. The variables investigated within this program included steel stirrups, and the shear span-to—effective depth ratio, as well as amount and distribution of CFRP。

144 Study on Construction Cost of Construction ProjectsHui LiAudit Department of Tianjin Polytechnic UniversityE-mail: lihui650122@AbstractChina is a country which has the largest investment amount in engineering construction in the world and which has the most construction projects. It is a significant subject for the extensive engineering managers to have effective engineering cost management in construction project management and to reasonably determine and control construction cost on the condition of ensuring construction quality and time limit.On the basis of the status quo of losing control in Chinese construction investment and of separation of technique and economy in engineering, and guided by basic theories of construction cost control, the author discusses control methods and application of construction cost, sets forth existing issues in construction cost control and influences of these issues on determination and control of construction cost, puts forward that construction cost control should reflect cost control of the entire construction process at the earlier stage of construction, and then introduces some procedures and methods of applying value project cost control at all stages of construction projects.Keywords: Construction cost, Cost control, Project1. Significance of the studyThe existing construction cost management system in China was formulated in 1950s, and improved in 1980s. Traditional construction cost managerial approach was one method brought in from the former Soviet Union based on unified quota of the country. It is characterized by the managerial approach of construction cost in the planned economy, which determines that it cannot adapt to requirements of the current market economy.Traditional construction cost managerial approach in China mainly includes two aspects, namely, determination approach of construction cost and control approach of construction cost. The traditional determination approach of construction cost mainly applied mechanically national or local unified quantity quota to determine the cost of a construction project. Although this approach has undergone reform of over 20 years, until now, influences of planned economy management mode have still been in existence in many regions. Control approach of our traditional construction cost is mainly to control settlement and alteration of construction cost, which is merely an approach to settle accounts after the event, and which cannot satisfy the purpose of saving resources and improving work. In recent years, requirements of developed countries on project investment have been to plan to control in advance and to control in the middle of an event, whose effects have proved to be effective. An actually scientific approach should be that construction cost control approach beforehand and after the event can eliminate or diminish labour in vain or poor efficiency and unnecessary resource degradation and methods applied in implementation of construction projects before or after the event.Considering the above situation, the academic circles put forward concept of cost management and control of the overall process as early as 1980s. They began to attach importance to prophase management of construction projects and take the initiative to conduct cost management. Afterwards, on July 1, 2003, implementation of <<Cost Estimate Norm for Bill of Quantity of Construction Works>> symbolized that cost estimate of China had entered a brand-new era that complied with development rules of market economy. From then on, concepts and approaches of Chinese cost management were really integrated with the international society.Losing control of construction project investment is a universal phenomenon in fixed investment field in China. A construction project consumes quite a lot of manpower, materials and machines, with large investment, long construction cycle, and strong synthesis, so it is related with economic interests of all construction parties and means a lot to national economy. Currently, in the field of Chinese project construction, there exists the status quo of separation of technique and economy. Most of engineers and technicians tend to regard construction cost as duty of financing andpreliminary budget personnel, and mistakenly believe that it has nothing to do with themselves. In the process of carrying out a project, they usually only focus on quality control and progress control, while they ignore control over investment in construction projects. If technicians ignore construction cost, and those who are in charge of construction cost have no knowledge in relevant technical construction connected with construction cost, then it is difficult for them to reasonably confirm and effectively control construction cost. Construction supervision investment control refers to managerial activities at the whole implementation state of the project, which attempts to guarantee realization of project investment targets with the premise of satisfying quality and progress. Investment targets are set at different stages with further progress of construction practice, and construction cost control runs through the entire process of project construction, but it should give prominence to the key points. Obviously, the key of construction cost control lies in investment decision-making and design stage before the construction, while after the investment decision is made, the key lies in the design. Life cycle of construction project includes construction cost and recurrent expenditure after the construction project is put into service, and discard and removal costs etc after usage period of the project. According to analysis of some western countries, usually design cost only amounts to less than 1% of life cycle of construction project. However, it is the cost of less than 1% that accounts for more than 75% of influences on construction cost. It is therefore obvious that, design quality is vital to benefits of the entire project construction.For a long time, construction cost control of the preliminary engineering of project construction has been ignored in China, while the primary energy of controlling construction cost has been focused upon auditing working drawing estimate, settling construction cost and settling itemized account during construction. Although this has its effect, after all, this had no difference from taking precautions after suffering a loss and getting half the result with twice the efforts. In order to effectively control construction cost, the emphasis of control should be firmly transferred to preliminary construction stage. At present, we should take all pains to grasp this significant stage so as to achieve maximum results with little effort.This article aims to analyze existing issues in cost control of the entire construction period through study on theoretical methods and practice of construction cost management. Especially, issues in cost control in the earlier period of construction deserve our research, so that we can explore corresponding reform measures to offer some references for construction project cost control.The situation of a construction project in which budgetary estimate exceeds estimation, budget exceeds budgetary estimate, and settlement exceeds budget, is a universal phenomenon in investment in fixed assets in China. Construction cost which is out of control adds to investment pressure, increases construction cost, reduces investment profit, affects investment decision-making, and, to a great extent, wastes the national finance, so it is likely to result in corruption or offence. Since the middle of 1950s, on the basis of summarizing practical experiences of fundamental construction battle line for several decades, we have conducted a series of reforms in construction field. Especially since May 1988, we have gradually implemented the system of construction supervision all over the country, which has had some positive effects upon reversing the phenomenon of losing control of a construction project in the implementation period. However, because that system is still in its starting stage, there hasn’t appeared a large batch of professional and socialized supervision teams. In addition, in projects in which construction supervision is carried out, there exist general phenomena, such as “emphasis on quality control at the construction stage and neglect of investment control”, and “emphasis on technical aspects of supervision and neglect of economic aspects of supervision”. In reality, rights of supervision tend to be confined to management of technical aspects, while management of economic aspects is firmly in control of proprietors. Meanwhile, lagging behind of existing construction cost management system is the primary cause for losing control of construction cost. Therefore, as a whole, the phenomenon of losing control over construction project cost is still quite serious, so it is necessary to conduct further study and make further analysis on major factors of current construction cost management and factors at all stages of a construction project that affect construction cost.2. Primary study contentAiming at the subject of “control of whole-process of construction project cost”, and based on lots of literature reviews about determination and control of construction project cost both at home and abroad, the author of this paper has collected extensively some relevant provincial and city reports and data after investigation. Afterwards, the author conducts the following work.1) To analyze formulation of construction project investment and to find out primary reasons for losing control over construction cost at all stages of a construction project.2) To study and analyze status quo and existing issues of current construction cost management, and study influences of these issues upon determination and control of a construction cost.3) To put forward effective approaches and methods as well application of value engineering of a construction project from its decision-making stage, design stage, construction stage to the final acceptance of construction stage.1454) To make clear significance, necessity and feasibility of cost control of a construction project so as to provide recommendations for improvement of construction cost management in China.2.1 Construction cost control theory and management mod eAccording to the new cost control theory, cost engineers are “professional persons who undertake cost estimate, cost control, marketing planning and scientific management”. Fields undertaken by cost engineers include such aspects as project management, project planning, progress management and profitability analysis etc of a project construction and its production process. Cost engineers offer service for control over life cycle expenditure, property facilities and production & manufacture of a construction project with their management technique with an overall cost.2.2 Current construction cost management model and theories in China2.2.1 Direct regulation and control of the governmentConsidering development process of quota, it can be discovered that quota has come into being, developed and become mature gradually with development of planned economy after foundation of PRC. Since China has carried out centralized management model of investment system for a long time, the government is not only a maker of macropolicy, but a participant of micro-project construction. Therefore, a unified quota with dense colour of planned economy is able to provide powerful methods and means for the government to carry out macro-investment regulation and control and micro-construction project management.2.2.2 Valuation basis for current construction costBasic materials for calculation of construction cost usually include construction cost quota, construction cost expense quota, cost index, basic unit price, quantities calculation rule and relevant economic rules and policies issued by competent departments of the government, etc. It includes index of estimate (budgetary estimate index), budgetary estimate quota, budgetary quota (comprehensive budgetary quota), expense quota (standard), labor quota, working-day norm, materials, budgetary price of facilities, direct price index of a project, material price index and cost index. And also included is valuation criterion of consumption quota and list of items in recent two years.2.2.3 Valuation model of current construction costValuation model is a basic aspect of construction cost management. Construction cost management is a governmental behavior, while valuation model is a means for a country to manage and control construction cost. There are two construction valuation models at present in China, namely, valuation model according to quota and one according to bill of quantities.2.2.3.1 Valuation model according to quotaValuation model according to quota is an effective model adopted during the transition period from planned economy to market economy. Determination of construction cost through valuation model according to quota prevents overrated valuation and standards and prices pressed down to some extent, because budgetary quota standardizes rate of consumption and a variety of documents stipulate manpower, materials, unit price of machines and all sorts of service fee norms, which reflects normativity, unitarity and rationality of construction cost. However, it has an inhibited effect upon market competition, and is not favorable for a construction enterprise to improve its technique, strengthen its management and enhance its labor efficiency and market competition.2.2.3.2 Valuation model according to bill of quantitiesValuation model according to bill of quantities is a construction cost determination model proposed recently. In this model, the government merely unifies project code, project name, unit of measurement and measurement rule of quantities. Each construction enterprise has its self-determination to quote a price according to its own situation in a tender offer, and price of building products is formed thereby in the process of bidding.2.3 Cost control in the process of implementationFor a long time, technique and economy has been separated in the field of project construction. Restrained by the planned economy, there lacks the economic concept in the minds of our engineers and technicians, because they regard reduction of construction cost as a duty of financial personnel which has nothing to do with themselves. However, the primary responsibility of financial and preliminary budget personnel is to act in accordance with financial system. Usually, they are not familiar with construction technique, and know little or even nothing about changes of various relations in project design, construction content and implementation of construction. Under such a circumstance, they have no choice but to mechanically work out or audit the expenditure from a financial perspective, which results in mutual separation of technique and economy. They just do what they do, which negatively reflects price of quantities of a project that has been completed, so it is difficult to control construction cost rationally and effectively.1462.4 Control of cost in the process of constructionImplementation stage of a construction project is a stage which requires the most assets in the whole process of a project construction, and is also a vital stage for pecuniary resources to transform into building entities. Cost control at the implementation stage refers to confine construction cost within a scheduled control scope through a scientific cost control theory and method on the condition of ensuring project quality and time limit. The process of generation of a building entity is inreversible, so if effective automatic control and precontrol cannot be conducted over construction cost, then economic loss might be caused that cannot be made up for.2.5 Analysis of major factors that affect construction cost at the stage of implementationImplementation stage of a project refers to the period from completion of construction documents design and examination and submission to the construction party to the final completion acceptance of the project and until it is put into use. According to the basic operation procedure of the implementation stage of a construction project, formation of a construction cost has to undergo such major aspects as bidding, contract signing and management, joint auditing of a shop drawing, investigation of a construction management plan, material management and completion settlement, etc. All these aspects affect construction cost settlement to different degrees. In that process, after evolving from budgetary price, price for successful bidding, refurbishing cost for a contract, the construction cost is finally determined in the form of settlement price for project completion. Factors affecting construction cost are various, but from the perspective of analysis of cost formation, there are primarily the following reasons.1) Influences of a project bidding. Bidding can determine price for successful bidding, while contract price is determined on the basis of price for successful bidding. If something goes wrong with bidding, then it might result in distortion of the price for bidding, and it is impossible to provide accurate and reliable foundation for cost control, and even result in losing control over the cost.2) Influences of contract signing and management. Determination of a contract price further makes precise target of cost control, and an initial draft of a contract term provides correct foundation and principles for cost control. After signing of a contract, contract items are regarded as foundation, which will have strict contract control over design changes at the construction stage, project measurement, payment of a construction debt, and construction compensation, etc, and which will ensure realization of a control target. Therefore, losing control over signing and management of a contract will necessarily result in losing control over construction cost.3) Influences of examination of construction management plan. Construction management plan is one of important foundations for determine a project bidding price and contract price. In the process of construction, adjustment of a contract price should also be determined according to construction management plan, because quality of construction management plan will directly affect quality and progress of a project. Therefore, losing control over examination of construction management plan will bring extremely unfavorable influences upon control over construction cost.4) Influences of material management. On one hand, material price is an important component of bidding price and contract price. On the other hand, material expense accounts for a large proportion in construction cost, because price of materials determine construction cost. Therefore, losing control over material management will necessarily result in losing control over construction cost.5) Influences of settlement, examination and verification of a project completion. Settlement, examination and verification is the final stage of a construction cost control at the implementation stage. A strict and meticulous settlement, examination and verification can ensure accuracy and authenticity of settlement cost of a project. According to previous analysis, we believe that all aspects of cost control can have effect upon formation of construction cost, among which bidding of a project, contract signing and management, examination of a construction management plan and management of materials all have decisive effects upon formation of construction cost, and are vital aspects in cost construction at the implementation stage of a project, so neglect of these four aspects is a direct cause for losing control over construction cost.In this paper, the author summarizes relevant issues in construction cost control at the decision-making stage of a construction project, at the design stage and construction stage, and puts forward principles or resolutions for handing such issues. Especially, as a method of combination of technique and economics, application of value engineering is elaborated at all stages, so that construction cost gets effective controlled. This paper cannot conclude all such issues existing, and also resolutions to resolve these issues cannot cover and contain everything, but with development of construction, new issues and new trains of thought will continue to emerge.ReferencesAminan Fayek. (1998). Competitive Bidding Strategy Model and Software System for Bid Preparation. Jounal of Construction Engineering and Management.Chen, Jianguo. (2001). Project Measurement and cost management. Shanghai: Tongji University Press.147Don R.Hansen & Maryanne M. Mowen. (2005). Cost Management: Accounting and Control.Dong, Shibo. (2003). Status Quo of Construction Cost Management Theory and Its Developmental Trend. Construction Cost Management, (5).Feng, Jingchun. (2000). Study on Counter Measures of Project Cost Management. Technical and Economic Development, (6).George J.Ritz. (1993). Total Construction Project Management.Gou, Zhiyuan. (2002). Thought on Integrated Control Approach of Construction Cost Management. Construction Cost Management, (6).Hao, Jianxin. (2002). American Construction Cost Management. Tianjin: Nankai University Press, 1, 51.Hu, Jianming. (2002). Discussion on Construction Cost Estimation Consultant Participating in Whole Course of Cost Management. Construction Cost Management, (5).Hu, Zhifeng. (2000). Overall Process Control on Construction Projects. Coal Enterprise Management, (7).Huang, Yonggen. (2004). Value Engineering and Its Application in Construction Cost Control. Construction Economics, (8).Ivor H Seeley. (1996). Building economics (fourth edition). Macmillan Press LTD.James A.Bent & Kenneth King Humphreys. (1996). Effective Project Management through Applied Cost and Schedule Control, Cost Engineering.Jan Emblemsavg. (2003). Life cycle Costing: sing Activity-based Costing and Monte Carlo Methods to Manage Future Costs and Risks. John wiley & sons, (5).Janice T. Dana. (1999). Standardized Quantity Recipe File for Quality and Cost Control.John E.Schaufelberger & Len Holm. (2001). Management of Construction Projects: A Constructor's Perspective.John Innes, Falconer Mitchell & Takeo Yoshikawa. (2000). Activity Costing for Engineers. Research Studies Press Ltd. John R.Canada, William G Sullivan, Dennis 3. Kulonda & John A.White. (2004). Capital Investment Analysis for Engineering and Management.Li, Tinggui. (2003). Study on Cost Management Model and Countermeasures of Construction project after China's entry into the WTO. Construction Cost Management.Liu, Guiwen & Shen, Qiping. (2001). A Study of Value Engineering Applications in China’s Construction Industry. Value Engineering, (3).Liu, Hongqing. (2003). About overall cost control. Shanxi Architecture, (29)6.Liu, Zhongying & Mao, Jian. Architecture Project Quantity List Quotation. Southeast University Press, 9.Luo, Dinglin. (1997). Determination and Control of Construction Project Cost at Home and Abroad. Beijing: Chemical Industry Press.Ma, Guanghong & Xu, Wei. (2003). Discussion on Application of Overall Cost Management Theory. Project Management, (4).Ma, Guanghong & Xu, Wei. (2003). Discussion on Application of Overall Cost Management Theory. Project Management, (4).Norton B R & McElligot C W. (1995). Value management in construction: a practical guide. Hampshire: Macmillan Press.Paul J. McVety. (1997). The Menu and the Cycle of Cost Control.Project Management Institute. (2004). A Guide to the Project Management Body of Knowledge.Qi, Anbang. (2000). Total Cost Management for Engineering Project. Tianjin: Nankai University Press.Qin, Aiguo. (1999). Study on Construction Cost Management. Economic Tribune, (22).Ren, Guoqiang & Yin, Yilin. (2003). The Feasibility Study on Life Cycle Cost Management in Terms of Paradigm Transformation. China Soft Science Magazine, (5).Ren, Hong. (2004). Cost Planning and Control of Construction Project. China Higher Education Press.Sidney M.Levy. (2002). Project Management in Construction.Stephen P Robbins & David A. Decenzo. (2002). Fundament of Management. Prentice Hall, Inc.148Takashi Ishikawa. (1996). Analogy by Abstraction: Case Retrieval and Adaptation for Inventive Design Expert Systems. Expert Systems with Application, (4)10.Tao, Xueming, Huang, Yunde & Xiong, Wei. (2004). Construction Cost Valuation and Management. China Architecture & Building Press, 2.Wang, Ailin. (2003). Value Engineering and Its Application in Constructional Engineering. Anhui Architecture, (5). Wang, Li & Xu, Zihua. (2004). Comparative Study on Construction Cost Models at Home and Abroad. Architecture Economics.Wang, Yulong. (1997). 2000 Cases on Issues of Construction Project Cost. Shanghai: Tongji University Press. Wang, Zhenqiang. (2002). British Construction Cost Management. Tianjin: Nankai University Press.Wang, Zhenqiang. (2002). Japanese Construction Cost Management. Tianjin: Nankai University Press, 4.Xiang, Ke & Luo, Feng. (2004). Cost Control of Design Stage. Sichuan Architecture, (2).Xu, Datu. (1997). Determination and Control of Construction Cost. Beijing: China Planning Press.Xu, Datu. (1997). Investment Control of Construction Project. Beijing: China Planning Press.Yin, Yilin. (2001). Determination and Control of Construction Cost. Beijing: China Planning Press.Zhang, Caijiang, Li, Kehua & Xu, Yongmei. Review of VE Theory and Practice in China and Some Deep Thinking about its Depression. Nankai Business Review, (1).Zhong, Guangen. (2004). Brief Discussion on Cost Control System in Projects of Commonwealth Nations.Zuo, Jin & Han, Hongyun. Actuality & Amelioration of Whole Life-cycle Value-chain in Architecture. Value Engineering, (6).149。