土木工程专业英语课文原文及对照翻译

Civil EngineeringCivil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities.土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑吻合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities.土木工程师建筑道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。

State-of-the-art report of bridge health monitoring AbstractThe damage diagnosis and healthmonitoring of bridge structures are active areas of research in recent years. Comparing with the aerospace engineering and mechanical engineering, civil engineering has the specialities of its own in practice. For example, because bridges, as well as most civil engineering structures, are large in size, and have quite lownatural frequencies and vibration levels, at low amplitudes, the dynamic responses of bridge structure are substantially affected by the nonstructural components, unforeseen environmental conditions, and changes in these components can easily to be confused with structural damage.All these give the damage assessment of complex structures such as bridges a still challenging task for bridge engineers. This paper firstly presents the definition of structural healthmonitoring system and its components. Then, the focus of the discussion is placed on the following sections:①the laboratory and field testing research on the damage assessment;②analytical developments of damage detectionmethods, including (a) signature analysis and pattern recognition approaches, (b) model updating and system identification approaches, (c) neural networks approaches; and③sensors and their optimum placements. The predominance and shortcomings of each method are compared and analyzed. Recent examples of implementation of structural health monitoring and damage identification are summarized in this paper. The key problem of bridge healthmonitoring is damage automatic detection and diagnosis, and it is the most difficult problem. Lastly, research and development needs are addressed.1 IntroductionDue to a wide variety of unforeseen conditions and circumstance, it will never be possible or practical to design and build a structure that has a zero percent probability of failure. Structural aging, environmental conditions, and reuse are examples of circumstances that could affect the reliability and thelife of a structure. There are needs of periodic inspections to detect deterioration resulting from normal operation and environmental attack or inspections following extreme events, such as strong-motion earthquakes or hurricanes. To quantify these system performance measures requires some means to monitor and evaluate the integrity of civil structureswhile in service. Since the Aloha Boeing 737 accident that occurred on April 28, 1988, such interest has fostered research in the areas of structural health monitoring and non-destructive damage detection in recent years.According to Housner, et al. (1997), structural healthmonitoring is defined as“the use ofin-situ,non-destructive sensing and analysis of structural characteristics, including the structural response, for detecting changes that may indicate damage or degradation”[1]. This definition also identifies the weakness. While researchers have attempted the integration of NDEwith healthmonitoring, the focus has been on data collection, not evaluation. What is needed is an efficient method to collect data from a structure in-service and process the data to evaluate key performance measures, such as serviceability, reliability, and durability. So, the definition byHousner, et al.(1997)should be modified and the structural health monitoring may be defined as“the use ofin-situ,nondestructive sensing and analysis of structural characteristics, including the structural response, for the purpose of identifying if damage has occurred, determining the location of damage, estimatingthe severityof damage and evaluatingthe consequences of damage on the structures”(Fig.1). In general, a structural health monitoring system has the potential to provide both damage detection and condition assessment of a structure.Assessing the structural conditionwithout removingthe individual structural components is known as nondestructive evaluation (NDE) or nondestructive inspection. NDE techniques include those involving acoustics, dye penetrating,eddy current, emission spectroscopy, fiber-optic sensors, fiber-scope, hardness testing, isotope, leak testing, optics, magnetic particles, magnetic perturbation, X-ray, noise measurements, pattern recognition, pulse-echo, ra-diography, and visual inspection, etc. Mostof thesetechniques have been used successfullyto detect location of certain elements, cracks orweld defects, corrosion/erosion, and so on. The FederalHighwayAdministration(FHWA, USA)was sponsoring a large program of research and development in new technologies for the nondestructive evaluation of highway bridges. One of the two main objectives of the program is to develop newtools and techniques to solve specific problems. The other is to develop technologies for the quantitative assessment of the condition of bridges in support of bridge management and to investigate howbest to incorporate quantitative condition information into bridge management systems. They hoped to develop technologies to quickly, efficiently, and quantitatively measure global bridge parameters, such as flexibility and load-carrying capacity. Obviously, a combination of several NDE techniques may be used to help assess the condition of the system. They are very important to obtain the data-base for the bridge evaluation.But it is beyond the scope of this review report to get into details of local NDE.Health monitoring techniques may be classified as global and local. Global attempts to simultaneously assess the condition of the whole structure whereas local methods focus NDE tools on specific structural components. Clearly, two approaches are complementaryto eachother. All such available informationmaybe combined and analyzed by experts to assess the damage or safety state of the structure.Structural health monitoring research can be categorized into the following four levels: (I) detecting the existence of damage, (II) findingthe location of damage, (III) estimatingthe extentof damage, and (IV) predictingthe remaining fatigue life. The performance of tasks of Level (III) requires refined structural models and analyses, local physical examination, and/or traditional NDE techniques. To performtasks ofLevel (IV) requires material constitutive information on a local level, materials aging studies, damage mechanics, and high-performance computing. With improved instrumentation and understanding of dynamics of complex structures, health monitoring and damage assessment of civil engineering structures has become more practical in systematic inspection andevaluation of these structures during the past two decades.Most structural health monitoringmethods under current investigation focus on using dynamic responses to detect and locate damage because they are global methods that can provide rapid inspection of large structural systems.These dynamics-based methods can be divided into fourgroups:①spatial-domain methods,②modal-domain methods,③time-domain methods, and④frequency- domain methods. Spatial-domain methods use changes of mass, damping, and stiffness matrices to detect and locate damage. Modal-domain methods use changes of natural frequencies, modal damping ratios, andmode shapesto detect damage. In the frequency domain method, modal quantities such as natural frequencies, damping ratio, and model shapes are identified.The reverse dynamic systemof spectral analysis and the generalized frequency response function estimated fromthe nonlinear auto-regressive moving average (NARMA) model were applied in nonlinear system identification. In time domainmethod, systemparameterswere determined fromthe observational data sampled in time. It is necessaryto identifythe time variation of systemdynamic characteristics fromtime domain approach if the properties of structural system changewith time under the external loading condition. Moreover, one can use model-independent methods or model-referenced methods to perform damage detection using dynamic responses presented in any of the four domains. Literature shows that model independent methods can detect the existence of damage without much computational efforts, butthey are not accurate in locating damage. On the otherhand, model-referencedmethods are generally more accurate in locating damage and require fewer sensors than model-independent techniques, but they require appropriate structural models and significant computational efforts. Although time-domain methods use original time-domain datameasured using conventional vibrationmeasurement equipment, theyrequire certain structural information and massive computation and are case sensitive. Furthermore, frequency- and modal-domain methods use transformed data,which contain errors and noise due totransformation.Moreover, themodeling and updatingofmass and stiffnessmatrices in spatial-domain methods are problematic and difficult to be accurate. There are strong developmenttrends that two or three methods are combined together to detect and assess structural damages.For example, several researchers combined data of static and modal tests to assess damages. The combination could remove the weakness of each method and check each other. It suits the complexity of damage detection.Structural health monitoring is also an active area of research in aerospace engineering, but there are significant differences among the aerospace engineering, mechanical engineering, and civil engineering in practice. For example,because bridges, as well as most civil engineering structures, are large in size, and have quite lownatural frequencies and vibration levels, at lowamplitudes, the dynamic responses of bridge structure are substantially affected by the non-structural components, and changes in these components can easily to be confused with structural damage. Moreover,the level of modeling uncertainties in reinforced concrete bridges can be much greater than the single beam or a space truss. All these give the damage assessment of complex structures such as bridges a still challenging task for bridge engineers. Recent examples of research and implementation of structural health monitoring and damage assessment are summarized in the following sections.2 Laboratory and field testing researchIn general, there are two kinds of bridge testing methods, static testing and dynamic testing. The dynamic testing includes ambient vibration testing and forced vibration testing. In ambient vibration testing, the input excitation is not under the control. The loading could be either micro-tremors, wind, waves, vehicle or pedestrian traffic or any other service loading. The increasing popularity of this method is probably due to the convenience of measuring the vibrationresponse while the bridge is under in-service and also due to the increasing availability of robust data acquisition and storage systems. Since the input is unknown, certain assumptions have to be made. Forced vibration testing involves application of input excitation of known force level at known frequencies. The excitation manners include electro-hydraulic vibrators, forcehammers, vehicle impact, etc. The static testing in the laboratory may be conducted by actuators, and by standard vehicles in the field-testing.we can distinguish that①the models in the laboratory are mainly beams, columns, truss and/or frame structures, and the location and severity of damage in the models are determined in advance;②the testing has demonstrated lots of performances of damage structures;③the field-testing and damage assessmentof real bridges are more complicated than the models in the laboratory;④the correlation between the damage indicator and damage type,location, and extentwill still be improved.3 Analytical developmentThe bridge damage diagnosis and health monitoring are both concerned with two fundamental criteria of the bridges, namely, the physical condition and the structural function. In terms of mechanics or dynamics, these fundamental criteria can be treated as mathematical models, such as response models, modal models and physical models.Instead of taking measurements directly to assess bridge condition, the bridge damage diagnosis and monitoring systemevaluate these conditions indirectly by using mathematical models. The damage diagnosis and health monitoring are active areas of research in recentyears. For example, numerous papers on these topics appear in the proceedings of Inter-national Modal Analysis Conferences (IMAC) each year, in the proceedings of International Workshop on Structural HealthMonitoring (once of two year, at Standford University), in the proceedings of European Conference on Smart materials and Structures and European Conference on Structural Damage AssessmentUsing Advanced Signal Processing Procedures, in the proceedings ofWorld Conferences of Earthquake Engineering, and in the proceedings of International Workshop on Structural Control, etc.. There are several review papers to be referenced, for examples,Housner, et al. (1997)provided an extensive summary of the state of the art in control and health monitoring of civil engineering structures[1].Salawu (1997)discussed and reviewed the use of natural frequency as a diagnostic parameter in structural assessment procedures using vibrationmonitoring.Doebling, Farrar, et al. (1998)presented a through review of the damage detection methods by examining changes in dynamic properties.Zou, TongandSteven (2000)summarized the methods of vibration-based damage and health monitoring for composite structures, especially in delamination modeling techniques and delamination detection.4 Sensors and optimum placementOne of the problems facing structural health monitoring is that very little is known about the actual stress and strains in a structure under external excitations. For example, the standard earthquake recordings are made ofmotions of the floors of the structure and no recordings are made of the actual stresses and strains in structural members. There is a need for special sensors to determine the actual performance of structural members. Structural health monitoring requires integrated sensor functionality to measure changes in external environmental conditions, signal processing functionality to acquire, process, and combine multi-sensor and multi-measured information. Individual sensors and instrumented sensor systems are then required to provide such multiplexed information.FuandMoosa (2000)proposed probabilistic advancing cross-diagnosis method to diagnosis-decision making for structural health monitoring. It was experimented in the laboratory respectively using a coherent laser radar system and a CCD high-resolution camera. Results showed that this method was promising for field application. Another new idea is thatneural networktechniques are used to place sensors. For example,WordenandBurrows (2001)used the neural network and methods of combinatorial optimization to locate and classify faults.The static and dynamic data are collected from all kinds of sensorswhich are installed on the measured structures.And these datawill be processed and usable informationwill be extracted. So the sensitivity, accuracy, and locations,etc. of sensors are very important for the damage detections. The more information are obtained, the damage identification will be conducted more easily, but the price should be considered. That’s why the sensors are determinedin an optimal ornearoptimal distribution. In aword, the theory and validation ofoptimumsensor locationswill still being developed.5 Examples of health monitoring implementationIn order for the technology to advance sufficiently to become an operational system for the maintenance and safety of civil structures, it is of paramount importance that new analytical developments are ultimately verified with appropriate data obtained frommonitoring systems, which have been implemented on civil structures, such as bridges.Mufti (2001)summarized the applications of SHM of Canadian bridge engineering, including fibre-reinforced polymers sensors, remote monitoring, intelligent processing, practical applications in bridge engineering, and technology utilization. Further study and applications are still being conducted now.FujinoandAbe(2001)introduced the research and development of SHMsystems at the Bridge and Structural Lab of the University of Tokyo. They also presented the ambient vibration based approaches forLaser DopplerVibrometer (LDV) and the applications in the long-span suspension bridges.The extraction of the measured data is very hard work because it is hard to separate changes in vibration signature duo to damage form changes, normal usage, changes in boundary conditions, or the release of the connection joints.Newbridges offer opportunities for developing complete structural health monitoring systems for bridge inspection and condition evaluation from“cradle to grave”of the bridges. Existing bridges provide challenges for applying state-of-the-art in structural health monitoring technologies to determine the current conditions of the structural element,connections and systems, to formulate model for estimating the rate of degradation, and to predict the existing and the future capacities of the structural components and systems. Advanced health monitoring systems may lead to better understanding of structural behavior and significant improvements of design, as well as the reduction of the structural inspection requirements. Great benefits due to the introduction of SHM are being accepted by owners, managers, bridge engineers,etc..6 Research and development needsMost damage detection theories and practices are formulated based on the following assumption: that failure or deterioration would primarily affect the stiffness and therefore affect the modal characteristics of the dynamic response of the structure. This is seldom true in practice, because①Traditional modal parameters (natural frequency, damping ratio and mode shapes, etc.) are not sensitive enough to identify and locate damage. The estimation methods usually assume that structures are linear and proportional damping systems.②Most currently used damage indices depend on the severity of the damage, which is impractical in the field. Most civil engineering structures, such as highway bridges, have redundancy in design and large in size with low natural frequencies. Any damage index should consider these factors.③Scaledmodelingtechniques are used in currentbridge damage detection. Asingle beam/girder models cannot simulate the true behavior of a real bridge. Similitude laws for dynamic simulation and testing should be considered.④Manymethods usually use the undamaged structural modal parameters as the baseline comparedwith the damaged information. This will result in the need of a large data storage capacity for complex structures. But in practice,there are majority of existing structures for which baseline modal responses are not available. Only one developed method(StubbsandKim (1996)), which tried to quantify damagewithout using a baseline, may be a solution to this difficulty. There is a lot of researchwork to do in this direction.⑤Seldommethods have the ability to distinguish the type of damages on bridge structures. To establish the direct relationship between the various damage patterns and the changes of vibrational signatures is not a simple work.Health monitoring requires clearly defined performance criteria, a set of corresponding condition indicators and global and local damage and deterioration indices, which should help diagnose reasons for changes in condition indicators. It is implausible to expect that damage can be reliably detected or tracked byusing a single damage index. We note that many additional localized damage indiceswhich relate to highly localized properties ofmaterials or the circumstances may indicate a susceptibility of deterioration such as the presence of corrosive environments around reinforcing steel in concrete, should be also integrated into the health monitoring systems.There is now a considerable research and development effort in academia, industry, and management department regarding global healthmonitoring for civil engineering structures. Several commercial structural monitoring systems currently exist, but further development is needed in commercialization of the technology. We must realize that damage detection and health monitoring for bridge structures by means of vibration signature analysis is a very difficult task. Itcontains several necessary steps, including defining indicators on variations of structural physical condition, dynamic testing to extract such indication parameters, defining the type of damages and remaining capacity or life of the structure, relating the parameters to the defined damage/aging. Unfortunately, to date, no one has accomplished the above steps. There is a lot of work to do in future.桥梁健康监测应用与研究现状摘要桥梁损伤诊断与健康监测是近年来国际上的研究热点,在实践方面,土木工程和航空航天工程、机械工程有明显的差别,比如桥梁结构以及其他大多数土木结构,尺寸大、质量重,具有较低的自然频率和振动水平,桥梁结构的动力响应极容易受到不可预见的环境状态、非结构构件等的影响,这些变化往往被误解为结构的损伤,这使得桥梁这类复杂结构的损伤评估具有极大的挑战性.本文首先给出了结构健康监测系统的定义和基本构成,然后集中回顾和分析了如下几个方面的问题:①损伤评估的室内实验和现场测试;②损伤检测方法的发展,包括:(a)动力指纹分析和模式识别方法, (b)模型修正和系统识别方法, (c)神经网络方法;③传感器及其优化布置等,并比较和分析了各自方法的优点和不足.文中还总结了健康监测和损伤识别在桥梁工程中的应用,指出桥梁健康监测的关键问题在于损伤的自动检测和诊断,这也是困难的问题;最后展望了桥梁健康监测系统的研究和发展方向.关键词:健康监测系统;损伤检测;状态评估;模型修正;系统识别;传感器优化布置;神经网络方法;桥梁结构1概述由于不可预见的各种条件和情况下，设计和建造一个结构将永远不可能或无实践操作性，它有一个失败的概率百分之零。

土木工程概论—中英对照对土木工程的发展起关键作用的，首先是作为工程物质基础的土木建筑材料，其次是随之发展起来的设计理论和施工技术。

每当出现新的优良的建筑材料时，土木工程就会有飞跃式的发展。

人们在早期只能依靠泥土、木料及其它天然材料从事营造活动，后来出现了砖和瓦这种人工建筑材料，使人类第一次冲破了天然建筑材料的束缚。

中国在公元前十一世纪的西周初期制造出瓦。

最早的砖出现在公元前五世纪至公元前三世纪战国时的墓室中。

砖和瓦具有比土更优越的力学性能，可以就地取材，而又易于加工制作。

砖和瓦的出现使人们开始广泛地、大量地修建房屋和城防工程等。

由此土木工程技术得到了飞速的发展。

直至18～19世纪，在长达两千多年时间里，砖和瓦一直是土木工程的重要建筑材料，为人类文明作出了伟大的贡献，甚至在目前还被广泛采用。

钢材的大量应用是土木工程的第二次飞跃。

十七世纪70年代开始使用生铁、十九世纪初开始使用熟铁建造桥梁和房屋，这是钢结构出现的前奏。

从十九世纪中叶开始，冶金业冶炼并轧制出抗拉和抗压强度都很高、延性好、质量均匀的建筑钢材，随后又生产出高强度钢丝、钢索。

于是适应发展需要的钢结构得到蓬勃发展。

除应用原有的粱、拱结构外，新兴的桁架、框架、网架结构、悬索结构逐渐推广，出现了结构形式百花争艳的局面。

建筑物跨径从砖结构、石结构、木结构的几米、几十米发展到钢结构的百米、几百米，直到现代的千米以上。

于是在大江、海峡上架起大桥，在地面上建造起摩天大楼和高耸铁塔，甚至在地面下铺设铁路，创造出前所未有的奇迹。

为适应钢结构工程发展的需要，在牛顿力学的基础上，材料力学、结构力学、工程结构设计理论等就应运而生。

施工机械、施工技术和施工组织设计的理论也随之发展，土木工程从经验上升成为科学，在工程实践和基础理论方面都面貌一新，从而促成了土木工程更迅速的发展。

十九世纪20年代，波特兰水泥制成后，混凝土问世了。

混凝土骨料可以就地取材，混凝土构件易于成型，但混凝土的抗拉强度很小，用途受到限制。

State-of-the-art report of bridge health monitoring AbstractThe damage diagnosis and healthmonitoring of bridge structures are active areas of research in recent years. Comparing with the aerospace engineering and mechanical engineering, civil engineering has the specialities of its own in practice. For example, because bridges, as well as most civil engineering structures, are large in size, and have quite lownatural frequencies and vibration levels, at low amplitudes, the dynamic responses of bridge structure are substantially affected by the nonstructural components, unforeseen environmental conditions, and changes in these components can easily to be confused with structural damage.All these give the damage assessment of complex structures such as bridges a still challenging task for bridge engineers. This paper firstly presents the definition of structural healthmonitoring system and its components. Then, the focus of the discussion is placed on the following sections:①the laboratory and field testing research on the damage assessment;②analytical developments of damage detectionmethods, including (a) signature analysis and pattern recognition approaches, (b) model updating and system identification approaches, (c) neural networks approaches; and③sensors and their optimum placements. The predominance and shortcomings of each method are compared and analyzed. Recent examples of implementation of structural health monitoring and damage identification are summarized in this paper. The key problem of bridge healthmonitoring is damage automatic detection and diagnosis, and it is the most difficult problem. Lastly, research and development needs are addressed.1 IntroductionDue to a wide variety of unforeseen conditions and circumstance, it will never be possible or practical to design and build a structure that has a zero percent probability of failure. Structural aging, environmental conditions, and reuse are examples of circumstances that could affect the reliability and the life of a structure. There are needs of periodic inspections to detect deterioration resulting from normal operation and environmental attack or inspections following extreme events, such as strong-motion earthquakes or hurricanes. To quantify these system performance measures requires some means to monitor and evaluate the integrity of civil structureswhile in service. Since the Aloha Boeing 737 accident that occurred on April28, 1988, such interest has fostered research in the areas of structural health monitoring and non-destructive damage detection in recent years.According to Housner, et al. (1997), structural healthmonitoring is defined as“the use ofin-situ,non-destructive sensing and analysis of structural characteristics, including the structural response, for detecting changes that may indicate damage or degradation”[1]. This definition also identifies the weakness. While researchers have attempted the integration of NDEwith healthmonitoring, the focus has been on data collection, not evaluation. What is needed is an efficient method to collect data from a structure in-service and process the data to evaluate key performance measures, such as serviceability, reliability, and durability. So, the definition byHousner, et al.(1997)should be modified and the structural health monitoring may be defined as“the use ofin-situ,nondestructive sensing and analysis of structural characteristics, including the structural response, for the purpose of identifying if damage has occurred, determining the location of damage, estimatingthe severityof damage and evaluatingthe consequences of damage on the structures”(Fig.1). In general, a structural health monitoring system has the potential to provide both damage detection and condition assessment of a structure.Assessing the structural conditionwithout removingthe individual structural components is known as nondestructive evaluation (NDE) or nondestructive inspection. NDE techniques include those involving acoustics, dye penetrating,eddy current, emission spectroscopy, fiber-optic sensors, fiber-scope, hardness testing, isotope, leak testing, optics, magnetic particles, magnetic perturbation, X-ray, noise measurements, pattern recognition, pulse-echo, ra-diography, and visual inspection, etc. Mostof these techniques have been used successfullyto detect location of certain elements, cracks orweld defects, corrosion/erosion, and so on. The FederalHighwayAdministration(FHWA, USA)was sponsoring a large program of research and development in new technologies for the nondestructive evaluation of highway bridges. One of the two main objectives of the program is to develop newtools and techniques to solve specific problems. The other is to develop technologies for the quantitative assessment of the condition of bridges in support of bridge management and to investigate howbest to incorporate quantitative condition information into bridge management systems. They hoped to develop technologies to quickly, efficiently, and quantitatively measure global bridge parameters, such as flexibility and load-carrying capacity. Obviously, a combination of several NDEtechniques may be used to help assess the condition of the system. They are very important to obtain the data-base for the bridge evaluation.But it is beyond the scope of this review report to get into details of local NDE.Health monitoring techniques may be classified as global and local. Global attempts to simultaneously assess the condition of the whole structure whereas local methods focus NDE tools on specific structural components. Clearly, two approaches are complementaryto eachother. All such available informationmaybe combined and analyzed by experts to assess the damage or safety state of the structure.Structural health monitoring research can be categorized into the following four levels: (I) detecting the existence of damage, (II) findingthe location of damage, (III) estimatingthe extentof damage, and (IV) predictingthe remaining fatigue life. The performance of tasks of Level (III) requires refined structural models and analyses, local physical examination, and/or traditional NDE techniques. To performtasks ofLevel (IV) requires material constitutive information on a local level, materials aging studies, damage mechanics, and high-performance computing. With improved instrumentation and understanding of dynamics of complex structures, health monitoring and damage assessment of civil engineering structures has become more practical in systematic inspection and evaluation of these structures during the past two decades.Most structural health monitoringmethods under current investigation focus on using dynamic responses to detect and locate damage because they are global methods that can provide rapid inspection of large structural systems.These dynamics-based methods can be divided into fourgroups:①spatial-domain methods,②modal-domain methods,③time-domain methods, and④frequency- domain methods. Spatial-domain methods use changes of mass, damping, and stiffness matrices to detect and locate damage. Modal-domain methods use changes of natural frequencies, modal damping ratios, andmode shapesto detect damage. In the frequency domain method, modal quantities such as natural frequencies, damping ratio, and model shapes are identified.The reverse dynamic systemof spectral analysis and the generalized frequency response function estimated fromthe nonlinear auto-regressive moving average (NARMA) model were applied in nonlinear system identification. In time domainmethod, systemparameterswere determined fromthe observational data sampled in time. It is necessaryto identifythe time variation of systemdynamic characteristics fromtime domain approach if the properties of structural systemchangewith time under the external loading condition. Moreover, one can use model-independent methods or model-referenced methods to perform damage detection using dynamic responses presented in any of the four domains. Literature shows that model independent methods can detect the existence of damage without much computational efforts, butthey are not accurate in locating damage. On the otherhand, model-referencedmethods are generally more accurate in locating damage and require fewer sensors than model-independent techniques, but they require appropriate structural models and significant computational efforts. Although time-domain methods use original time-domain datameasured using conventional vibrationmeasurement equipment, theyrequire certain structural information and massive computation and are case sensitive. Furthermore, frequency- and modal-domain methods use transformed data,which contain errors and noise due totransformation.Moreover, themodeling and updatingofmass and stiffnessmatrices in spatial-domain methods are problematic and difficult to be accurate. There are strong developmenttrends that two or three methods are combined together to detect and assess structural damages.For example, several researchers combined data of static and modal tests to assess damages. The combination could remove the weakness of each method and check each other. It suits the complexity of damage detection.Structural health monitoring is also an active area of research in aerospace engineering, but there are significant differences among the aerospace engineering, mechanical engineering, and civil engineering in practice. For example,because bridges, as well as most civil engineering structures, are large in size, and have quite lownatural frequencies and vibration levels, at lowamplitudes, the dynamic responses of bridge structure are substantially affected by the non-structural components, and changes in these components can easily to be confused with structural damage. Moreover,the level of modeling uncertainties in reinforced concrete bridges can be much greater than the single beam or a space truss. All these give the damage assessment of complex structures such as bridges a still challenging task for bridge engineers. Recent examples of research and implementation of structural health monitoring and damage assessment are summarized in the following sections.2 Laboratory and field testing researchIn general, there are two kinds of bridge testing methods, static testing and dynamic testing. The dynamic testing includes ambient vibration testing and forcedvibration testing. In ambient vibration testing, the input excitation is not under the control. The loading could be either micro-tremors, wind, waves, vehicle or pedestrian traffic or any other service loading. The increasing popularity of this method is probably due to the convenience of measuring the vibrationresponse while the bridge is under in-service and also due to the increasing availability of robust data acquisition and storage systems. Since the input is unknown, certain assumptions have to be made. Forced vibration testing involves application of input excitation of known force level at known frequencies. The excitation manners include electro-hydraulic vibrators, force hammers, vehicle impact, etc. The static testing in the laboratory may be conducted by actuators, and by standard vehicles in the field-testing.we can distinguish that①the models in the laboratory are mainly beams, columns, truss and/or frame structures, and the location and severity of damage in the models are determined in advance;②the testing has demonstrated lots of performances of damage structures;③the field-testing and damage assessmentof real bridges are more complicated than the models in the laboratory;④the correlation between the damage indicator and damage type,location, and extentwill still be improved.3Analytical developmentThe bridge damage diagnosis and health monitoring are both concerned with two fundamental criteria of the bridges, namely, the physical condition and the structural function. In terms of mechanics or dynamics, these fundamental criteria can be treated as mathematical models, such as response models, modal models and physical models.Instead of taking measurements directly to assess bridge condition, the bridge damage diagnosis and monitoring systemevaluate these conditions indirectly by using mathematical models. The damage diagnosis and health monitoring are active areas of research in recentyears. For example, numerous papers on these topics appear in the proceedings of Inter-national Modal Analysis Conferences (IMAC) each year, in the proceedings of International Workshop on Structural HealthMonitoring (once of two year, at Standford University), in the proceedings of European Conference on Smart materials and Structures and European Conference on Structural Damage AssessmentUsing Advanced Signal Processing Procedures, in the proceedings ofWorld Conferences of Earthquake Engineering, and in the proceedings of International Workshop on Structural Control, etc.. There are several review papers to be referenced, for examples,Housner, et al. (1997)provided an extensive summary ofthe state of the art in control and health monitoring of civil engineering structures[1].Salawu (1997)discussed and reviewed the use of natural frequency as a diagnostic parameter in structural assessment procedures using vibration monitoring.Doebling, Farrar, et al. (1998)presented a through review of the damage detection methods by examining changes in dynamic properties.Zou, TongandSteven (2000)summarized the methods of vibration-based damage and health monitoring for composite structures, especially in delamination modeling techniques and delamination detection.4Sensors and optimum placementOne of the problems facing structural health monitoring is that very little is known about the actual stress and strains in a structure under external excitations. For example, the standard earthquake recordings are made ofmotions of the floors of the structure and no recordings are made of the actual stresses and strains in structural members. There is a need for special sensors to determine the actual performance of structural members. Structural health monitoring requires integrated sensor functionality to measure changes in external environmental conditions, signal processing functionality to acquire, process, and combine multi-sensor and multi-measured information. Individual sensors and instrumented sensor systems are then required to provide such multiplexed information.FuandMoosa (2000)proposed probabilistic advancing cross-diagnosis method to diagnosis-decision making for structural health monitoring. It was experimented in the laboratory respectively using a coherent laser radar system and a CCD high-resolution camera. Results showed that this method was promising for field application. Another new idea is thatneural networktechniques are used to place sensors. For example,WordenandBurrows (2001)used the neural network and methods of combinatorial optimization to locate and classify faults.The static and dynamic data are collected from all kinds of sensorswhich are installed on the measured structures.And these datawill be processed and usable informationwill be extracted. So the sensitivity, accuracy, and locations,etc. of sensors are very important for the damage detections. The more information are obtained, the damage identification will be conducted more easily, but the price should be considered. That’s why the sensors are determined in an optimal ornearoptimal distribution. In aword, the theory and validation ofoptimumsensor locationswill still being developed.5 Examples of health monitoring implementationIn order for the technology to advance sufficiently to become an operational system for the maintenance and safety of civil structures, it is of paramount importance that new analytical developments are ultimately verified with appropriate data obtained frommonitoring systems, which have been implemented on civil structures, such as bridges.Mufti (2001)summarized the applications of SHM of Canadian bridge engineering, including fibre-reinforced polymers sensors, remote monitoring, intelligent processing, practical applications in bridge engineering, and technology utilization. Further study and applications are still being conducted now.FujinoandAbe(2001)introduced the research and development of SHMsystems at the Bridge and Structural Lab of the University of Tokyo. They also presented the ambient vibration based approaches forLaser DopplerVibrometer (LDV) and the applications in the long-span suspension bridges.The extraction of the measured data is very hard work because it is hard to separate changes in vibration signature duo to damage form changes, normal usage, changes in boundary conditions, or the release of the connection joints.Newbridges offer opportunities for developing complete structural health monitoring systems for bridge inspection and co ndition evaluation from“cradle to grave”of the bridges. Existing bridges provide challenges for applying state-of-the-art in structural health monitoring technologies to determine the current conditions of the structural element,connections and systems, to formulate model for estimating the rate of degradation, and to predict the existing and the future capacities of the structural components and systems. Advanced health monitoring systems may lead to better understanding of structural behavior and significant improvements of design, as well as the reduction of the structural inspection requirements. Great benefits due to the introduction of SHM are being accepted by owners, managers, bridge engineers, etc..6 Research and development needsMost damage detection theories and practices are formulated based on the following assumption: that failure or deterioration would primarily affect the stiffness and therefore affect the modal characteristics of the dynamic response of the structure. This is seldom true in practice, because①Traditional modal parameters (natural frequency, damping ratio and mode shapes, etc.) are not sensitive enough to identifyand locate damage. The estimation methods usually assume that structures are linear and proportional damping systems.②Most currently used damage indices depend on the severity of the damage, which is impractical in the field. Most civil engineering structures, such as highway bridges, have redundancy in design and large in size with low natural frequencies. Any damage index should consider these factors.③Scaledmodelingtechniques are used in currentbridge damage detection. Asingle beam/girder models cannot simulate the true behavior of a real bridge. Similitude laws for dynamic simulation and testing should be considered.④Manymethods usually use the undamaged structural modal parameters as the baseline comparedwith the damaged information. This will result in the need of a large data storage capacity for complex structures. But in practice,there are majority of existing structures for which baseline modal responses are not available. Only one developed method(StubbsandKim (1996)), which tried to quantify damagewithout using a baseline, may be a solution to this difficulty. There is a lot of researchwork to do in this direction.⑤Seldommethods have the ability to distinguish the type of damages on bridge structures. To establish the direct relationship between the various damage patterns and the changes of vibrational signatures is not a simple work.Health monitoring requires clearly defined performance criteria, a set of corresponding condition indicators and global and local damage and deterioration indices, which should help diagnose reasons for changes in condition indicators. It is implausible to expect that damage can be reliably detected or tracked by using a single damage index. We note that many additional localized damage indiceswhich relate to highly localized properties ofmaterials or the circumstances may indicate a susceptibility of deterioration such as the presence of corrosive environments around reinforcing steel in concrete, should be also integrated into the health monitoring systems.There is now a considerable research and development effort in academia, industry, and management department regarding global healthmonitoring for civil engineering structures. Several commercial structural monitoring systems currently exist, but further development is needed in commercialization of the technology. We must realize that damage detection and health monitoring for bridge structures by means of vibration signature analysis is a very difficult task. Itcontains several necessary steps, including defining indicators on variations of structural physical condition, dynamic testing to extract such indication parameters,defining the type of damages and remaining capacity or life of the structure, relating the parameters to the defined damage/aging. Unfortunately, to date, no one has accomplished the above steps. There is a lot of work to do in future.桥梁健康监测应用与研究现状摘要桥梁损伤诊断与健康监测是近年来国际上的研究热点,在实践方面,土木工程和航空航天工程、机械工程有明显的差别,比如桥梁结构以及其他大多数土木结构,尺寸大、质量重,具有较低的自然频率和振动水平,桥梁结构的动力响应极容易受到不可预见的环境状态、非结构构件等的影响,这些变化往往被误解为结构的损伤,这使得桥梁这类复杂结构的损伤评估具有极大的挑战性.本文首先给出了结构健康监测系统的定义和基本构成,然后集中回顾和分析了如下几个方面的问题:①损伤评估的室内实验和现场测试;②损伤检测方法的发展,包括:(a)动力指纹分析和模式识别方法, (b)模型修正和系统识别方法, (c)神经网络方法;③传感器及其优化布置等,并比较和分析了各自方法的优点和不足.文中还总结了健康监测和损伤识别在桥梁工程中的应用,指出桥梁健康监测的关键问题在于损伤的自动检测和诊断,这也是困难的问题;最后展望了桥梁健康监测系统的研究和发展方向.关键词:健康监测系统;损伤检测;状态评估;模型修正;系统识别;传感器优化布置;神经网络方法;桥梁结构1概述由于不可预见的各种条件和情况下，设计和建造一个结构将永远不可能或无实践操作性，它有一个失败的概率百分之零。

Civil engineeringCivil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works like bridges, roads, canals, dams, and buildings.[1][2][3] Civil engineering is the oldest engineering discipline after military engineering,[4] and it was defined to distinguish non-military engineering from military engineering.[5] It is traditionally broken into several sub-disciplines including environmental engineering, geotechnical engineering, structural engineering, transportation engineering, municipal or urban engineering, water resources engineering, materials engineering, coastal engineering,[4] surveying, and construction engineering.[6] Civil engineering takes place on all levels: in the public sector from municipal through to national governments, and in the private sector from individual homeowners through to international companies.History of the civil engineering professionSee also: History of structural engineeringEngineering has been an aspect of life since the beginnings of human existence. The earliest practices of Civil engineering may have commenced between 4000 and 2000 BC in Ancient Egypt and Mesopotamia (Ancient Iraq) when humans started to abandon a nomadic existence, thus causing a need for the construction of shelter. During this time, transportation became increasingly important leading to the development of the wheel and sailing.Until modern times there was no clear distinction between civil engineering and architecture, and the term engineer and architect were mainly geographical variations referring to the same person, often used interchangeably.[7]The construction of Pyramids in Egypt (circa 2700-2500 BC) might be considered the first instances of large structure constructions. Other ancient historic civil engineering constructions include the Parthenon by Iktinos in Ancient Greece (447-438 BC), theAppian Way by Roman engineers (c. 312 BC), the Great Wall of China by General Meng T'ien under orders from Ch'in Emperor Shih Huang Ti (c. 220 BC)[6] and the stupas constructed in ancient Sri Lanka like the Jetavanaramaya and the extensive irrigation works in Anuradhapura. The Romans developed civil structures throughout their empire, including especially aqueducts, insulae, harbours, bridges, dams and roads.In the 18th century, the term civil engineering was coined to incorporate all things civilian as opposed to military engineering.[5]The first self-proclaimed civil engineer was John Smeaton who constructed the Eddystone Lighthouse.[4][6]In 1771 Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Though there was evidence of some technical meetings, it was little more than a social society.In 1818 the Institution of Civil Engineers was founded in London, and in 1820 the eminent engineer Thomas Telford became its first president. The institution received a Royal Charter in 1828, formally recognising civil engineering as a profession. Its charter defined civil engineering as:the art of directing the great sources of power in nature for the use and convenience of man, as the means of production and of traffic in states, both for external and internal trade, as applied in the construction of roads, bridges, aqueducts, canals, river navigation and docks for internal intercourse and exchange, and in the construction of ports, harbours, moles, breakwaters and lighthouses, and in the art of navigation by artificial power for the purposes of commerce, and in the construction and application of machinery, and in the drainage of cities and towns.[8] The first private college to teach Civil Engineering in the United States was Norwich University founded in 1819 by Captain Alden Partridge.[9] The first degree in Civil Engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835.[10] The first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatchin 1905.History of civil engineeringCivil engineering is the application of physical and scientific principles, and its history is intricately linked to advances in understanding of physics and mathematics throughout history. Because civil engineering is a wide ranging profession, including several separate specialized sub-disciplines, its history is linked to knowledge of structures, materials science, geography, geology, soils, hydrology, environment, mechanics and other fields.Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stone masons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and seldom supplanted by advances. Structures, roads and infrastructure that existed were repetitive, and increases in scale were incremental.[12]One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering is the work of Archimedes in the 3rd century BC, including Archimedes Principle, which underpins our understanding of buoyancy, and practical solutions such as Archimedes' screw. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation (volume) computations.[13]Civil engineers typically possess an academic degree with a major in civil engineering. The length of study for such a degree is usually three to five years and the completed degree is usually designated as a Bachelor of Engineering, though some universities designate the degree as a Bachelor of Science. The degree generally includes units covering physics, mathematics, project management, design and specific topics in civil engineering. Initially such topics cover most, if not all, of thesub-disciplines of civil engineering. Students then choose to specialize in one or more sub-disciplines towards the end of the degree.[14]While anUndergraduate (BEng/BSc) Degree will normally provide successful students with industry accredited qualification, some universities offer postgraduate engineering awards (MEng/MSc) which allow students to further specialize in their particular area of interest within engineering.[15]In most countries, a Bachelor's degree in engineering represents the first step towards professional certification and the degree program itself is certified by a professional body. After completing a certified degree program the engineer must satisfy a range of requirements (including work experience and exam requirements) before being certified. Once certified, the engineer is designated the title of Professional Engineer (in the United States, Canada and South Africa), Chartered Engineer (in most Commonwealth countries), Chartered Professional Engineer (in Australia and New Zealand), or European Engineer (in much of the European Union). There are international engineering agreements between relevant professional bodies which are designed to allow engineers to practice across international borders.The advantages of certification vary depending upon location. For example, in the United States and Canada "only a licensed engineer may prepare, sign and seal, and submit engineering plans and drawings to a public authority for approval, or seal engineering work for public and private clients.".[16]This requirement is enforced by state and provincial legislation such as Quebec's Engineers Act.[17]In other countries, no such legislation exists. In Australia, state licensing of engineers is limited to the state of Queensland. Practically all certifying bodies maintain a code of ethics that they expect all members to abide by or risk expulsion.[18] In this way, these organizations play an important role in maintaining ethical standards for the profession. Even in jurisdictions where certification has little or no legal bearing on work, engineers are subject to contract law. In cases where an engineer's work fails he or she may be subject to the tort of negligence and, in extreme cases, thecharge of criminal negligence.[citation needed] An engineer's work must also comply with numerous other rules and regulations such as building codes and legislation pertaining to environmental law.CareersThere is no one typical career path for civil engineers. Most people who graduate with civil engineering degrees start with jobs that require a low level of responsibility, and as the new engineers prove their competence, they are trusted with tasks that have larger consequences and require a higher level of responsibility. However, within each branch of civil engineering career path options vary. In some fields and firms, entry-level engineers are put to work primarily monitoring construction in the field, serving as the "eyes and ears" of senior design engineers; while in other areas, entry-level engineers perform the more routine tasks of analysis or design and interpretation. Experienced engineers generally do more complex analysis or design work, or management of more complex design projects, or management of other engineers, or into specialized consulting, including forensic engineering.In general, civil engineering is concerned with the overall interface of human created fixed projects with the greater world. General civil engineers work closely with surveyors and specialized civil engineers to fit and serve fixed projects within their given site, community and terrain by designing grading, drainage, pavement, water supply, sewer service, electric and communications supply, and land divisions. General engineers spend much of their time visiting project sites, developing community consensus, and preparing construction plans. General civil engineering is also referred to as site engineering, a branch of civil engineering that primarily focuses on converting a tract of land from one usage to another. Civil engineers typically apply the principles of geotechnical engineering, structural engineering, environmental engineering, transportation engineering and construction engineering toresidential, commercial, industrial and public works projects of all sizes and levels of construction翻译：土木工程土木工程是一个专业的工程学科，包括设计，施工和维护与环境的改造，涉及了像桥梁，道路，河渠，堤坝和建筑物工程交易土木工程是最古老的军事工程后，工程学科，它被定义为区分军事工程非军事工程的学科它传统分解成若干子学科包括环境工程，岩土工程，结构工程，交通工程，市或城市工程，水资源工程，材料工程，海岸工程，勘测和施工工程等土木工程的范围涉及所有层次：从市政府到国家，从私人部门到国际公司。

土木工程专业英语课文翻译陶燕王文萱第九单元Civil engineering,the oldest of the engineering specialties,is the planning，design，construction，and management of the built environment. This environment includes all structures built according to scientific principles，from irrigation and drainage systems torocket-launching facilities.土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

Civil engineers build roads，bridges，tunnels，dams,harbors，power plants，water and sewage systems,hospitals,schools，mass transit,and other public facilities essential to modern society and largepopulation concentrations. They also build privately owned facilities such as airports，railroads，pipelines,skyscrapers，and other large structures designed forindustrial，commercial，or residential use. In addition,civil engineers plan，design，and build complete citiesand towns，and more recently have been planning and designing space platforms to house self-containedcommunities.土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。

PAVEMENT PROBLEMS CAUSEDBY COLLAPSIBLE SUBGRADESBy Sandra L. Houston,1 Associate Member, ASCE(Reviewed by the Highway Division)ABSTRACT: Problem subgrade materials consisting of collapsible soils are -mon in arid environments, which have climatic conditions and depositional and weathering processes favorable to their formation. Included herein is a discussion of predictive techniques that use commonly available laboratory equipment and testing methods for obtaining reliable estimates of the volume change for these problem soils. A method for predicting relevant stresses and corresponding collapse strains for typical pavement subgrades is presented. Relatively simple methods ofevaluating potential volume change, based on results of familiar laboratory tests, are used.INTRODUCTIONWhen a soil is given free access to water, it may decrease in volume,increase in volume, or do nothing. A soil that increases in volume is calleda swelling or expansive soil, and a soil that decreases in volume is called a collapsible soil. The amount of volume change that occurs depends on thesoil type and structure, the initial soil density, the imposed stress state, and the degree and extent of wetting. Subgrade materials comprised of soils that change volume upon wetting have caused distress to highways since the be- ginning of the professional practice and have cost many millions of dollarsin roadway repairs. The prediction of the volume changes that may occur inthe field is the first step in making an economic decision for dealing with these problem subgrade materials.Each project will have different design considerations, economic con-straints, and risk factors that will have to be taken into account. However, with a reliable method for making volume change predictions, the best design relative to the subgrade soils becomes a matter of economic comparison, anda much more rational design approach may be made. For example, typical techniques for dealing with expansive clays include: (1) In situ treatments with substances such as lime, cement, or fly-ash; (2) seepage barriers and/or drainage systems; or (3) a computing of the serviceability loss and a mod- ification of the design to "accept" the anticipated expansion. In order to make the most economical decision, the amount of volume change (especially non- uniform volume change) must be accurately estimated, and the degree of road roughness evaluated from these data. Similarly, alternative design techniques are available for any roadway problem.The emphasis here will be placed on presenting economical and simplemethods for: (1) Determining whether the subgrade materials are collapsible; and (2) estimating the amount of volume change that is likely to occur in the 'Asst. Prof., Ctr. for Advanced Res. in Transp., Arizona State Univ., Tempe, AZ 85287.Note. Discussion open until April 1, 1989. To extend the closing date one month, a written request must be filed with the ASCE Manager of Journals. The manuscript for this paper was submitted for review and possible publication on February 3, 1988.This paper is part of the Journal of Transportation.Engineering, Vol. 114, No. 6,November, 1988. ASCE, ISSN 0733-947X/88/0006-0673/$1.00 + $.15 per page. Paper No. 22902.673field for the collapsible soils. Then this information will place the engineer in a position to make a rational design decision. Collapsible soils are fre- quently encountered in an arid climate. The depositional process and for- mation of these soils, and methods for identification and evaluation of the amount of volume change that may occur, will be discussed in the following sections.COLLAPSIBLE SOILSFormation of Collapsible SoilsCollapsible soils have high void ratios and low densities and are typically cohesionless or only slightly cohesive. In an arid climate, evaporation greatly exceeds rainfall. Consequently, only the near-surface soils become wettedfrom normal rainfall. It is the combination of the depositional process andthe climate conditions that leads to the formation of the collapsible soil. Although collapsible soils exist in nondesert regions, the dry environment in which evaporation exceeds precipitation is very favorable for the formationof the collapsible structure.As the soil dries by evaporation, capillary tension causes the remainingwater to withdraw into the soil grain interfaces, bringing with it soluble salts, clay, and silt particles. As the soil continues to dry, these salts, clays, and silts come out of solution, and "tack-weld" the larger grains together. This leads to a soil structure that has high apparent strength at its low, natural water content. However, collapse of the "cemented" structure may occurupon wetting because the bonding material weakens and softens, and the soilis unstable at any stress level that exceeds that at which the soil had been previously wetted. Thus, if the amount of water made available to the soilis increased above that which naturally exists, collapse can occur at fairly low levels of stress, equivalent only to overburden soil pressure. Additional loads, such as traffic loading or the presence of a bridge structure, add to the collapse, especially of shallow collapsible soil. The triggering mechanism for collapse, however, is the addition of water.Highway Problems Resulting from Collapsible SoilsNonuniform collapse can result from either a nonhomogeneous subgradedeposit in which differing degrees of collapse potential exist and/or fromnonuniform wetting of subgrade materials. When differential collapse of subgrade soils occurs, the result is a rough, wavy surface, and potentially many miles of extensively damaged highway. There have been several re-ported cases for which differential collapse has been cited as the cause of roadway or highway bridge distress. A few of these in the Arizona and New Mexico region include sections of 1-10 near Benson, Arizona, and sectionsof 1-25 in the vicinity of Algadonas, New Mexico (Lovelace et al. 1982; Russman 1987). In addition to the excessive waviness of the roadway sur-face, bridge foundations failures, such as the Steins Pass Highway bridge,1-10, in Arizona, have frequently been identified with collapse of foundation soils.Identification of Collapsible SoilsThere have been many techniques proposed for identifying a collapsiblesoil problem. These methods range from qualitative index tests conducted on674disturbed samples, to response to wetting tests conducted on relatively un- disturbed samples, to in situ meausrement techniques. In all cases, the en- gineer must first know if the soils may become wetted to a water contentabove their natural moisture state, and if so, what the extent of the potential wetted zone will be. Most methods for identifying collapsible soils are only qualitative in nature, providing no information on the magnitude of the col- lapse strain potential. These qualitative methods are based on various func- tions of dry density, moisture content, void ratio, specific gravity, and At- terberg limits.In situ measurement methods appear promising in some cases, in that many researchers feel that sample disturbance is greatly reduced, and that a more nearly quantitative measure of collapse potential is obtainable. However,in situ test methods for collapsible soils typically suffer from the deficien- cy of an unknown extent and degree of wetting during the field test. This makes a quantitative measurement difficult because the zone of materialbeing influenced is not well-known, and, therefore, the actual strains, in- duced by the addition of stress and water, are not well-known. In addition,the degree of saturation achieved in the field test is variable and usually unknown.Based on recently conducted research, it appears that the most reliablemethod for identifying a collapsible soil problem is to obtain the best quality undisturbed sample possible and to subject this sample to a response to wet- ting test in the laboratory. The results of a simple oedometer test will indicate whether the soil is collapsible and, at the same time, give a direct measureof the amount of collapse strain potential that may occur in the field. Potential problems associated with the direct sampling method include sample distur-bance and the possibility that the degree of saturation achieved in the field will be less than that achieved in the laboratory test.The quality of an undisturbed sample is related most strongly to the arearatio of the tube that is used for sample collection. The area ratio is a measure of the ratio of the cross-sectional area of the sample collected to the cross- sectional area of the sample tube. A thin-walled tube sampler by definitionhas an area ratio of about 10-15%. Although undisturbed samples are best obtained through the use of thin-walled tube samplers, it frequently occursthat these stiff, cemented collapsible soils, especially those containing gravel, cannot be sampled unless a tube with a much thicker wall is used. Samplers having an area ratio as great as 56% are commonly used for Arizona col-lapsible soils. Further, it may take considerable hammering of the tube todrive the sample. The result is, of course, some degree of sample distur- bance, broken.bonds, densification, and a correspondingly reduced collapse measured upon laboratory testing. However, for collapsible soils, which are compressive by definition, the insertion of the sample tube leads to local shear failure at the base of the cutting edge, and, therefore, there is less sample disturbance than would be expected for soils that exhibit general shear failure (i.e., saturated clays or dilative soils). Results of an ongoing study of sample disturbance for collapsible soils indicate that block samples some- times exhibit somewhat higher collapse strains compared to thick-walled tube samples. Block samples are usually assumed to be the very best obtainable undisturbed samples, although they are frequently difficult-to-impossible to obtain, especially at substantial depths. The overall effect of sample distur- bance is a slight underestimate of the collapse potential for the soil.675译文：湿陷性地基引起的路面问题...摘要：在干旱环境中，湿陷性土壤组成的路基材料是很常见的，干旱环境中的气候条件、沉积以与风化作用都有利于湿陷性土的形成。

成绩徐州工程学院08 级土木(1) 班课程考试试卷考试科目专业英语考试时间学生姓名所在院系土木学院任课教师徐州工程学院印制Stability of Slopes9.1 IntroductionTranslational slips tend to occur where the adjacent stratum is at a relatively shallow depth below the surface of the slope:the failure surface tends to be plane and roughly parallel to the pound slips usually occur where the adjacent stratum is at greater depth，the failure surface consisting of curved and plane sections．In practice, limiting equilibrium methods are used in the analysis of slope stability. It is considered that failure is on the point of occurring along an assumed or a known failure surface．The shear strength required to maintain a condition of limiting equilibrium is compared with the available shear strength of the soil，giving the average factor of safety along the failure surface．The problem is considered in two dimensions，conditions of plane strain being assumed．It has been shown that a two-dimensional analysis gives a conservative result for a failure on a three-dimensional(dish-shaped) surface．9.2 Analysis for the Case of φu =0This analysis, in terms of total stress，covers the case of a fully saturated clay under undrained conditions, i.e. For the condition immediately after construction．Only moment equilibrium is considered in the analysis．In section, the potential failure surface is assumed to be a circular arc. A trial failure surface(centre O，radius r and length L awhere F is the factor of safety with respect to shear strength．Equating moments about O：Therefore(9.1)The moments of any additional forces must be taken into account．In the event of a tension crackdeveloping ，as shown in Fig.9.2，the arc length L a is shortened and a hydrostatic force will act normal to the crack if the crack fills with water．It is necessary to analyze the slope for a number of trial failure surfaces in order that the minimum factor of safety can be determined．Based on the principle of geometric similarity，Taylor[9.9]published stability coefficients for the analysis of homogeneous slopes in terms of total stress．For a slope of height H the stability coefficient (N s) for the failure surface along which the factor of safety is a minimum is(9.2)For the case ofφu =0，values of N ss depends on the slope angleβand the depth factor D，where DH is the depth to a firm stratum．Gibson and Morgenstern [9.3] published stability coefficients for slopes in normally consolidated clays in which the undrained strength c u(φu =0) varies linearly with depth．Example 9.1A 45°slope is excavated to a depth of 8 m in a deep layer of saturated clay of unit weight 19 kN／m3:the relevant shear strength parameters are c u =65 kN／m2 andφuIn Fig.9.4, the cross-sectional area ABCD is 70 m2.Weight of soil mass=70×19=1330kN／mThe centroid of ABCD is 4.5 m from O．The angle AOC is 89.5°and radius OC is 12.1 m．The arc length ABC is calculated as 18.9m．The factor of safety is given by：This is the factor of safety for the trial failure surface selected and is not necessarily the minimum factor of safety．The minimum factor of safety can be estimated by using Equation 9.2.From Fig.9.3，β=45°and assuming that D is large，the value of N s9.3 The Method of Slicesαand the height, measured on the centre-1ine,is h. The factor of safety is defined as the ratio of the available shear strength(τf)to the shear strength(τm) which must be mobilized to maintain a condition of limiting equilibrium, i.e.The factor of safety is taken to be the same for each slice，implying that there must be mutual support between slices，i.e. forces must act between the slices．The forces (per unit dimension normal to the section) acting on a slice are：1.The total weight of the slice，W=γb h (γsat where appropriate)．2.The total normal force on the base，N (equal to σl)．In general thisforce has two components，the effective normal force N'(equal toσ'l ) and the boundary water force U(equal to ul )，where u is the pore water pressure at the centre of the base and l is the length of the base．3.The shear force on the base，T=τm l.4.The total normal forces on the sides, E1 and E2.5.The shear forces on the sides，X1 and X2.Any external forces must also be included in the analysis．The problem is statically indeterminate and in order to obtain a solution assumptions must be made regarding the interslice forces E and X：the resulting solution for factor of safety is not exact．Considering moments about O，the sum of the moments of the shear forces T on the failure arc AC must equal the moment of the weight of the soil mass ABCD．For any slice the lever arm of W is rsinα,therefore∑Tr=∑Wr sinαNow,For an analysis in terms of effective stress，Or(9.3)where L a is the arc length AC．Equation 9.3 is exact but approximations are introduced in determining the forces N'．For a given failure arc the value of F will depend on the way in which the forces N' areestimated．The Fellenius SolutionIn this solution it is assumed that for each slice the resultant of the interslice forces is zero．The solution involves resolving the forces on each slice normal to the base，i.e.N'=WCOSα-ulHence the factor of safety in terms of effective stress (Equation 9.3) is given by(9.4)The components WCOSαand Wsinαcan be determined graphically for each slice．Alternatively，the value of αcan be measured or calculated．Again，a series of trial failure surfaces must be chosen in order to obtain the minimum factor of safety．This solution underestimates the factor of safety：the error，compared with more accurate methods of analysis，is usually within the range 5-2%.For an analysis in terms of total stress the parameters C u andφu are used and the value of u in Equation 9.4 is zero．If φu=0 ,the factor of safety is given by(9.5)As N’ does not appear in Equation 9.5 an exact value of F is obtained．The Bishop Simplified SolutionIn this solution it is assumed that the resultant forces on the sides of theslices are horizontal，i.e.X l-X2=0For equilibrium the shear force on the base of any slice isResolving forces in the vertical direction:(9.6)It is convenient to substitutel=b secαFrom Equation 9.3，after some rearrangement，(9.7)The pore water pressure can be related to the total ‘fill pressure’ at anypoint by means of the dimensionless pore pressure ratio，defined as(9.8)(γsat where appropriate)．For any slice,Hence Equation 9.7 can be written:(9.9)As the factor of safety occurs on both sides of Equation 9.9,a process of successive approximation must be used to obtain a solution but convergence is rapid．Due to the repetitive nature of the calculations and the need to select an adequate number of trial failure surfaces，the method of slices is particularly suitable for solution by computer．More complex slope geometry and different soil strata can be introduced．In most problems the value of the pore pressure ratio r u is not constant over the whole failure surface but，unless there are isolated regions of high pore pressure，an average value(weighted on an area basis) is normally used in design．Again，the factor of safety determined by this method is an underestimate but the error is unlikely to exceed 7％and in most cases is less than 2％．Spencer [9.8] proposed a method of analysis in which the resultant Interslice forces are parallel and in which both force and moment equilibrium are satisfied．Spencer showed that the accuracy of the Bishop simplified method，in which only moment equilibrium is satisfied, is due to the insensitivity of the moment equation to the slope of the interslice forces．Dimensionless stability coefficients for homogeneous slopes，based on Equation 9.9，have been published by Bishop and Morgenstern [9.2].It can be shown that for a given slope angle and given soil properties th e factor of safety varies linearly with γu and can thus be expressed asF=m-nγu(9.10)where，m and n are the stability coefficients．The coefficients，m and n arefunctions ofβ,φ’，the dimensionless number c'/γand the depth factor D.Example 9.2Using the Fellenius method of slices，determine the factor of safety，in terms of effective stress，of the slope shown in Fig.9.6 for the given failure surface．The unit weight of the soil，both above and below the water table，is 20 kN／m 3 and the relevant shear strength parameters are c’=10 kN/m2andφ’=29°. W) of each slice is given byW=γbh=20×1.5×h=30h kN／mThe height h for each slice is set off below the centre of the base and thenormal and tangential components hcosαand hsinαWcosα=30h cosαW sinα=30h sinαThe pore water pressure at the centre of the base of each slice is taken to beγw z w，where z w is the vertical distance of the centre point below the water table (as shown in figure)．This procedure slightly overestimates t he pore water pressure which strictly should be) γw z e，where z e is the vertical distance below the point of intersection of the water table and the equipotential through the centre of the slice base．The error involved is on the safe side．The arc length (L a) is calculated as 14.35 mm．The results are given inTable 9.1∑Wcosα=30×17.50=525kN／m∑W sinα=30×8.45=254kN／m∑(wcos α-ul)=525—132=393kN／m9.4 Analysis of a Plane Translational SlipIt is assumed that the potential failure surface is parallel to the surface of the slope and is at a depth that is small compared with the length of the slope. The slope can then be considered as being of infinite length，with end effects being ignored．The slope is inclined at angle βmz (0<m<1)above the failure plane．Steady seepage is assumed to be taking place in a direction parallel to the slope．The forces on the sides of any vertical slice are equal and opposite and the stress conditions are the same at every point on the failure plane．In terms of effective stress，the shear strength of the soil along the failure plane isand the factor of safety isThe expressions forσ,τandμare:The following special cases are of interest．If c’=0 and m=0 (i.e. the soilbetween the surface and the failure plane is not fully saturated),then(9.11)If c’=0 and m=1(i.e. the water table coincides with the surface of the slope)，then：(9.12)It should be noted that when c’=0 the factor of safety is independent ofthe depth z．If c’ is greater than zero，the factor of safety is a function of z, and βmay exceedφ’ provided z is less than a critical value．For a total stress analysis the shear strength parameters c u andφu are used with a zero value of u. Example 9.3A long natural slope in a fissured overconsolidated clay is inclined at 12°to the horizontal．The water table is at the surface and seepage is roughly parallel to the slope．A slip has developed on a plane parallel to the surface at a depth of 5 m．The saturated unit weight of the clay is 20 kN／m3．The peak strength parameters are c’=10 kN/m2andφ’=26°；the residual strength parameters are c r’=0 andφr’=18°.Determine the factor of safety alo ng the slip plane(a)in terms of the peak strength parameters (b)in terms of the residual strength parameters．With the water table at the surface(m=1)，at any point on the slip plane，Using the peak strength parameters，Then the factor of safety is given byUsing the residual strength parameters，the factor of safety can beobtained from Equation 9.12:9.5 General Methods of AnalysisMorgenstern and Price[9.4]developed a general analysis in which all boundary and equilibrium conditions are satisfied and in which the failure surface may be any shape，circular，non-circular or compound．The soil mass above the failure plane is divided into sections by a number of vertical planes and the problem is rendered statically determinate by assuming a relationship between the forces E and X on the vertical boundaries between each section．This assumption is of the formX=λf(x)E (9.13)where f(x)is an arbitrary function describing the pattern in which the ratio X/E varies across the soil mas s andλis a scale factor．The value ofλis obtained as part of the solution along with the factor of safety F．The values of the forces E and X and the point of application of E can be determined at each vertical boundary．For any assumed function f(x) it is necessary to examine the solution in detail to ensure that it is physically reasonable (i.e. no shear failure or tension must be implied within the soil mass above the failure surface). The choice of the function f(x) does not appear to influence the computed value of F by more than about 5% and f(x)=l is a common assumption．The analysis involves a complex process of iteration for the values ofλ and F，described byMorgenstern and Price[9.5]，and the use of a computer is essential.Bell [9.1] proposed a method of analysis in which all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape．The soil mass is divided into a number of vertical slices and statical determinacy is obtained by means of an assumed distribution of normal stress along the failure surface．Sarma [9.6] developed a method，based on the method of slices，in which the critical earthquake acceleration required to produce a condition of limiting equilibrium is determined．An assumed distribution of vertical interslice forces is used in the analysis．Again，all the conditions of equilibrium are satisfied and the assumed failure surface may be of any shape．The static factor of safety is the factor by which the shear strength of the soil must be reduced such that the critical acceleration is zero．The use of a computer is also essential for the Bell and Sarma methods and all solutions must be checked to ensure that they are physically acceptable．References[9.1]Bell,J,M.(1968):’General Slope Stability Analysis’, Journal ASCE,V01.94,No.SM6.：‘Stability Coefficients for Earth Slopes Geotechnique，．’，Vo1.1 5,No.1.‘A Numerical Method for Solving the Equations of Stability of General Slip Surfaces’Computer Journal，Voi.9,P.388．[9.6]Sarma,S.K. (1973):’Stability Analysis of Embankments and Slopes’,Geotechnique，Vo1.23，No.2.[9.7]Skempton,A.W.(1970):’First-Time Slides in Overconsolidated Clays’(Technical Note)，[9.8]Spencer，E．(1 967)：‘A Method of Analysis of the Stability of Embankments Assuming Parallel Inter-SliceForces’，Geotechnique，．[9.9]Taylor,D.W.(1937):’Stability of Earth Slopes’,Journal of the Boston Society of Civil Engineers，Vo1.24,No.3边坡稳定9.1 引言重力和渗透力易引起天然边坡、开挖形成的边坡、堤防边坡和土坝的不稳定性。

第一课 土木工程学土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。

他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。

此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。

土木一词来源于拉丁文词“公民”。

在 年，英国人 为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。

自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。

领域。

因为包含范围太广，土木工程学又被细分为大量的技术专业。

不同类型的工程需要多种不同土木工程专业技术。

一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。

岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。

环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。

交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。

同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。

从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。

根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。

贯穿任何给定项目，土木工程师都需要大量使用计算机。

计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者 ）并对其进行管理。

参考译文第一单元第一部分钢筋混凝土混凝土混凝土由水，砂，石子和水泥构成。

这些不同的，分散的材料混合在一起就构成了一种坚硬的大块状物体（形状各异），有着良好的性能。

混凝土被用作建筑材料已有150年的历史。

它的普遍应用主要由于以下几点：（1）恶劣环境下的耐久性（包括耐水）（2）极易被浇铸成不同的形状和尺寸（3）相对经济实惠，极易获得（4）有极强的抗压能力但众所周知，与其较强的抗压强度相比，混凝土抗拉和抗弯强度较低。

因此，每当荷载，限制收缩或是温度发生变化，产生的拉应力超过混凝土的拉伸强度时，就会有裂缝出现。

在结构应用方面，通常的做法是利用钢筋来抵抗拉力或者是给混凝土施加压力来抵消这些拉力。

预应力混凝土对混凝土构件加载之前，对其进行压缩的方法称为预应力。

把钢筋和混凝土使用很强的力结合在一起就被称为预应力混凝土。

预应力混凝土的优点如下：1.在预应力操作过程中，混凝土和钢筋经过严格测试，较低的安全系数也是正当的。

2.混凝土中可容许的工作压力通常是抗压强度的三分之一，从而使保证金来弥补劣质混凝土在临界区发生的风险。

3.预应力减少风险，是由于混凝土在预应力操作期间产生的应力可能是其抗压强度的50%到75%。

今天，预应力混凝土被应用于建筑物，地下结构，电视塔，浮动储藏器和海上结构，电站，核反应堆容器和包括拱形桥和斜拉桥在内的各种桥梁系统当中。

这说明了预应力概念的多方面适应性以及对它的广泛应用。

所有这些结构的发展和建造的成功都是由于材料技术的进步，尤其是预应力钢和在估计预应力长期和短期损失方面积累的知识。

钢筋钢筋是一种极好的建筑材料。

与其他材料相比，钢筋有着较高的抗拉强度。

尽管在体积上是木材的十倍以上。

钢筋有着较高的弹性模量，因此在荷载下容易发生小的变形。

到目前为止所描述的钢筋的特性只适用于温度保持在70F上下的情况，大约从30F到110F。

这个温度区间覆盖了大多数结构的运行状况，但搞清楚当温度远远超出正常水平时所发生的情况仍然非常重要。

土木工程专业英语课文原文及对照翻译土木工程师建造道路、桥梁、隧道、水坝、港口、发电厂、水和污水系统、医院、学校、大众交通和其他对现代社会和大量人口集中地区至关重要的公共设施。

他们还建造私人拥有的设施，如机场、铁路、管道、摩天大楼和其他为工业、商业或住宅使用而设计的大型结构。

此外，土木工程师规划、设计和建造完整的城市和城镇，最近还在规划和设计太空平台，以容纳自给自足的社区。

___ passes the planning。

design。

n。

and management of the built ___ scientific principles。

from ___ are essential to modern society。

such as roads。

bridges。

___。

dams。

and hospitals.___ public facilities。

civil engineers also design and build privately-owned structures。

including airports。

railroads。

pipelines。

skyscrapers。

and other ___。

and ___.Overall。

___ civil engineers。

our modern infrastructure and public facilities would not exist.___。

n。

and maintenance of public and private infrastructure。

This includes roads。

bridges。

pipelines。

dams。

ports。

power plants。

water supply and sewage systems。

hospitals。

schools。

___。

and other structures that are essential to modern ___ as airports。

第一课土木工程学土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。

他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。

此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。

土木一词来源于拉丁文词“公民”。

在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。

自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。

领域。

因为包含范围太广，土木工程学又被细分为大量的技术专业。

不同类型的工程需要多种不同土木工程专业技术。

一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。

岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。

环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。

交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。

同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。

从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。

根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。

贯穿任何给定项目，土木工程师都需要大量使用计算机。

计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。

Civil engineering introduction papers[英语原文]Abstract: the civil engineering is a huge discipline, but the main one is building, building whether in China or abroad, has a long history, long-term development process. The world is changing every day, but the building also along with the progress of science and development. Mechanics findings, material of update, ever more scientific technology into the building. But before a room with a tile to cover the top of the house, now for comfort, different ideas, different scientific, promoted the development of civil engineering, making it more perfect.[key words] : civil engineering; Architecture; Mechanics, Materials.Civil engineering is build various projects collectively. It was meant to be and "military project" corresponding. In English the history of Civil Engineering, mechanical Engineering, electrical Engineering, chemical Engineering belong to to Engineering, because they all have MinYongXing. Later, as the project development of science and technology, mechanical, electrical, chemical has gradually formed independent scientific, to Engineering became Civil Engineering of specialized nouns. So far, in English, to Engineering include water conservancy project, port Engineering, While in our country, water conservancy projects and port projects also become very close and civil engineering relatively independent branch. Civil engineering construction of object, both refers to that built on the ground, underground water engineering facilities, also refers to applied materials equipment and conduct of the investigation, design and construction, maintenance, repair and other professional technology.Civil engineering is a kind of with people's food, clothing, shelter and transportation has close relation of the project. Among them with "live" relationship is directly. Because, to solve the "live" problem must build various types of buildings. To solve the "line, food and clothes" problem both direct side, but also a indirect side. "Line", must build railways, roads, Bridges, "Feed", must be well drilling water, water conservancy, farm irrigation, drainage water supply for the city, that is direct relation. Indirectly relationship is no matter what you do, manufacturing cars, ships, or spinning and weaving, clothing, or even production steel, launch satellites, conducting scientific research activities are inseparable from build various buildings, structures and build all kinds of project facilities.Civil engineering with the progress of human society and development, yet has evolved into large-scale comprehensive discipline, it has out many branch, such as: architectural engineering, the railway engineering, road engineering, bridge engineering, special engineering structure, waterand wastewater engineering, port engineering, hydraulic engineering, environment engineering disciplines. [1]Civil engineering as an important basic disciplines, and has its important attributes of: integrated, sociality, practicality, unity. Civil engineering for the development of national economy and the improvement of people's life provides an important material and technical basis, for many industrial invigoration played a role in promoting, engineering construction is the formation of a fixed asset basic production process, therefore, construction and real estate become in many countries and regions, economic powerhouses.Construction project is housing planning, survey, design, construction of the floorboard. Purpose is for human life and production provide places.Houses will be like a man, it's like a man's life planning environment is responsible by the planners, Its layout and artistic processing, corresponding to the body shape looks and temperament, is responsible by the architect, Its structure is like a person's bones and life expectancy, the structural engineer is responsible, Its water, heating ventilation and electrical facilities such as the human organ and the nerve, is by the equipment engineer is responsible for. Also like nature intact shaped like people, in the city I district planning based on build houses, and is the construction unit, reconnaissance unit, design unit of various design engineers and construction units comprehensive coordination and cooperation process.After all, but is structural stress body reaction force and the internal stress and how external force balance. Building to tackle, also must solve the problem is mechanical problems. We have to solve the problem of discipline called architectural mechanics. Architectural mechanics have can be divided into: statics, material mechanics and structural mechanics three mechanical system. Architectural mechanics is discussion and research building structure and component in load and other factors affecting the working condition of, also is the building of intensity, stiffness and stability. In load, bear load and load of structure and component can cause the surrounding objects in their function, and the object itself by the load effect and deformation, and there is the possibility of damage, but the structure itself has certain resistance to deformation and destruction of competence, and the bearing capacity of the structure size is and component of materials, cross section, and the structural properties of geometry size, working conditions and structure circumstance relevant. While these relationships can be improved by mechanics formula solved through calculation.Building materials in building and has a pivotal role. Building material is with human society productivity and science and technologyimproves gradually developed. In ancient times, the human lives, the line USES is the rocks andTrees. The 4th century BC, 12 ~ has created a tile and brick, humans are only useful synthetic materials made of housing. The 17th century had cast iron and ShouTie later, until the eighteenth century had Portland cement, just make later reinforced concrete engineering get vigorous development. Now all sorts of high-strength structural materials, new decoration materials and waterproof material development, criterion and 20th century since mid organic polymer materials in civil engineering are closely related to the widely application. In all materials, the most main and most popular is steel, concrete, lumber, masonry. In recent years, by using two kinds of material advantage, will make them together, the combination of structure was developed. Now, architecture, engineering quality fit and unfit quality usually adopted materials quality, performance and using reasonable or not have direct connection, in meet the same technical indicators and quality requirements, under the precondition of choice of different material is different, use method of engineering cost has direct impact.In construction process, building construction is and architectural mechanics, building materials also important links. Construction is to the mind of the designer, intention and idea into realistic process, from the ancient hole JuChao place to now skyscrapers, from rural to urban country road elevated road all need through "construction" means. A construction project, including many jobs such as dredging engineering, deep foundation pit bracing engineering, foundation engineering, reinforced concrete structure engineering, structural lifting project, waterproofing, decorate projects, each type of project has its own rules, all need according to different construction object and construction environment conditions using relevant construction technology, in work-site.whenever while, need and the relevant hydropower and other equipment composition of a whole, each project between reasonable organizing and coordination, better play investment benefit. Civil engineering construction in the benefit, while also issued by the state in strict accordance with the relevant construction technology standard, thus further enhance China's construction level to ensure construction quality, reduce the cost for the project.Any building built on the surface of the earth all strata, building weight eventually to stratum, have to bear. Formation Support building the rocks were referred to as foundation, and the buildings on the ground and under the upper structure of self-respect and liable to load transfer to the foundation of components or component called foundation. Foundation, and the foundation and the superstructure is a building of three inseparable part. According to the function is different, but in load, under the action of them are related to each other, is theinteraction of the whole. Foundation can be divided into natural foundation and artificial foundation, basic according to the buried depth is divided into deep foundation and shallow foundation. , foundation and foundation is the guarantee of the quality of the buildings and normal use close button, where buildings foundation in building under loads of both must maintain overall stability and if the settlement of foundation produce in building scope permitted inside, and foundation itself should have sufficient strength, stiffness and durability, also consider repair methods and the necessary foundation soil retaining retaining water and relevant measures. [3]As people living standard rise ceaselessly, the people to their place of building space has become not only from the number, and put forward higher requirement from quality are put car higher demands that the environment is beautiful, have certain comfort. This needs to decorate a building to be necessary. If architecture major engineering constitutes the skeleton of the building, then after adornment building has become the flesh-and-blood organism, final with rich, perfect appearance in people's in front, the best architecture should fully embody all sorts of adornment material related properties, with existing construction technology, the most effective gimmick, to achieve conception must express effect. Building outfit fix to consider the architectural space use requirement, protect the subject institutions from damage, give a person with beautifulenjoying, satisfy the requirements of fire evacuation, decorative materials and scheme of rationality, construction technology and economic feasibility, etc. Housing construction development and at the same time, like housing construction as affecting people life of roads, Bridges, tunnels has made great progress.In general civil engineering is one of the oldest subjects, it has made great achievements, the future of the civil engineering will occupy in people's life more important position. The environment worsening population increase, people to fight for survival, to strive for a more comfortable living environment, and will pay more attention to civil engineering. In the near future, some major projects extimated to build, insert roller skyscrapers, across the oceanBridges, more convenient traffic would not dream. The development of science and technology, and the earth is deteriorating environment will be prompted civil engineering to aerospace and Marine development, provide mankind broader space of living. In recent years, engineering materials mainly is reinforced concrete, lumber and brick materials, in the future, the traditional materials will be improved, more suitable for some new building materials market, especially the chemistry materials will promote the construction of towards a higher point. Meanwhile, design method of precision, design work of automation, information and intelligent technology of introducing, will be people have a morecomfortable living environment. The word, and the development of the theory and new materials, the emergence of the application of computer, high-tech introduction to wait to will make civil engineering have a new leap.This is a door needs calm and a great deal of patience and attentive professional. Because hundreds of thousands, even hundreds of thousands of lines to building each place structure clearly reflected. Without a gentle state of mind, do what thing just floating on the surface, to any a building structure, to be engaged in business and could not have had a clear, accurate and profound understanding of, the nature is no good. In this business, probably not burn the midnight oil of courage, not to reach the goal of spirit not to give up, will only be companies eliminated.This is a responsible and caring industry. Should have a single responsible heart - I one's life in my hand, thousands of life in my hand. Since the civil, should choose dependably shoulder the responsibility.Finally, this is a constant pursuit of perfect industry. Pyramid, spectacular now: The Great Wall, the majestic... But if no generations of the pursuit of today, we may also use the sort of the oldest way to build this same architecture. Design a building structure is numerous, but this is all experienced centuries of clarification, through continuous accumulation, keep improving, innovation obtained. And such pursuit, not confined in the past. Just think, if the design of a building can be like calculation one plus one equals two as simple and easy to grasp, that was not for what? Therefore, a civil engineer is in constant of in formation. One of the most simple structure, the least cost, the biggest function. Choose civil, choosing a steadfast diligence, innovation, pursuit of perfect path.Reference:[1] LuoFuWu editor. Civil engineering (professional). Introduction to wuhan. Wuhan university of technology press. 2007[2] WangFuChuan, palace rice expensive editor. Construction engineering materials. Beijing. Science and technology literature press. 2002[3] jiang see whales, zhiming editor. Civil engineering introduction of higher education press. Beijing.. 1992土木工程概论 [译文]摘要：土木工程是个庞大的学科，但最主要的是建筑，建筑无论是在中国还是在国外，都有着悠久的历史，长期的发展历程。

Unit 3 (从第三段开始)现代水泥发明于1824年，称为波特兰水泥。

它是石灰石和粘土的混合物，加热后磨成粉末。

在或靠近施工现场，将水泥与砂、骨料（小石头、压碎的岩石或砾石）、水混合而制成混凝土。

不同比例的配料会制造出不同强度和重量的混凝土。

混凝土的用途很多，可以浇筑、泵送甚至喷射成各种形状。

混凝土具有很大的抗压强度，而钢材具有很大的抗拉强度。

这样，两种材料可以互补。

They also complement each other in another way: they have almost the same rate of contraction and expansion. They therefore can work together in situations where（在…情况下）both compression and tension are factors（主要因素）. Steel rods（钢筋）are embedded in（埋入）concrete to make reinforced concrete in concrete beams or structures where tension will develop （出现）. Concrete and steel also form such a strong bond - the force that unites（粘合）them - that the steel cannot slip（滑移）with the concrete. Still（还有）another advantage is that steel does not rust in concrete. Acid（酸）corrodes steel, whereas concrete has an alkaline chemical reaction, the opposite of acid.它们也以另外一种方式互补：它们几乎有相同的收缩率和膨胀率。

英文原文：Concrete structure reinforcement designSheyanb oⅠWangchenji aⅡⅠFoundation Engineering Co., Ltd. Heilongjiang DongyuⅡHeilongjiang Province, East Building Foundation Engineering Co., Ltd. CoalAbstract：structure in the long-term natural environment and under the use environment's function, its function is weaken inevitably gradually, our structural engineering's duty not just must finish the building earlier period the project work, but must be able the science appraisal structure damage objective law and the degree, and adopts the effective method guarantee structure the security use, that the structure reinforcement will become an important work. What may foresee will be the 21st century, the human building also by the concrete structure, the steel structure, the bricking-up structure and so on primarily, the present stage I will think us in the structure reinforcement this aspect research should also take this as the main breakthrough direction.Key word：Concrete structure reinforcement bricking-up structure reinforcement steel structure reinforcement1 Concrete structure reinforcementConcrete structure's reinforcement divides into the direct reinforcement and reinforces two kinds indirectly, when the design may act according to the actual condition and the operation requirements choice being suitable method and the necessary technology.1.1the direct reinforcement's general method1）Enlarges the section reinforcement lawAdds the concretes cast-in-place level in the reinforced concrete member in bending compression zone, may increase the section effective height, the expansion cross sectional area, thus enhances the component right section anti-curved, the oblique section anti-cuts ability and the section rigidity, plays the reinforcement reinforcement the role.In the suitable muscle scope, the concretes change curved the component right section supporting capacity increase along with the area of reinforcement and the intensity enhance. In the original component right section ratio of reinforcement not too high situation, increases the main reinforcement area to be possible to propose the plateau component right section anti-curved supporting capacity effectively. Is pulled in the section the area to add the cast-in-place concrete jacket to increase the component section, through new Canada partial and original component joint work, but enhances the component supporting capacity effectively, improvement normal operational performance.Enlarges the section reinforcement law construction craft simply, compatible, and has the mature design and the construction experience; Is suitable in Liang, the board, the column, the wall and the general structure concretes reinforcement; But scene construction's wet operating time is long, to produces has certain influence with the life, and after reinforcing the building clearance has certain reduction.2) Replacement concretes reinforcement lawThis law's merit with enlarges the method of sections to be close, and after reinforcing, does not affect building's clearance, but similar existence construction wet operating time long shortcoming; Is suitable somewhat low or has concretes carrier's and so on serious defect Liang, column in the compression zone concretes intensity reinforcement.3) the caking outsourcing section reinforcement lawOutside the Baotou Steel Factory reinforcement is wraps in the section or the steel plate is reinforced component's outside, outside the Baotou Steel Factory reinforces reinforced concrete Liang to use the wet outsourcing law generally, namely uses the epoxy resinification to be in the milk and so on methods with to reinforce the section the construction commission to cake a whole, after the reinforcement component, because is pulled with the compressed steel cross sectional area large scale enhancement, therefore right section supporting capacity and section rigidity large scale enhancement.This law also said that the wet outside Baotou Steel Factory reinforcement law, the stress is reliable, the construction is simple, the scene work load is small, but is big with the steel quantity, and uses in above not suitably 600C in the non-protection's situation the high temperature place; Is suitable does not allow in the use obviously to increase the original component section size, but requests to sharpen its bearing capacity large scale the concrete structure reinforcement.4) Sticks the steel reinforcement lawOutside the reinforced concrete member in bending sticks the steel reinforcement is (right section is pulled in the component supporting capacity insufficient sector area, right section compression zone or oblique section) the superficial glue steel plate, like this may enhance is reinforced component's supporting capacity, and constructs conveniently.This law construction is fast, the scene not wet work or only has the plastering and so on few wet works, to produces is small with the life influence, and after reinforcing, is not remarkable to the original structure outward appearance and the original clearance affects, but the reinforcement effect is decided to a great extent by the gummy craft and the operational level; Is suitable in the withstanding static function, and is in the normal humidity environment to bend or the tension member reinforcement.5) Glue fibre reinforcement plastic reinforcement lawOutside pastes the textile fiber reinforcement is pastes with the cementing material the fibre reinforcement compound materials in is reinforced the component to pull the region, causes it with to reinforce the section joint work, achieves sharpens the component bearing capacity the goal. Besides has glues the steel plate similar merit, but also has anticorrosive muddy, bears moistly, does not increase the self-weight of structure nearly, durably, the maintenance cost low status merit, but needs special fire protection processing, is suitable in each kind of stress nature concrete structure component and the general construction.This law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.6) Reeling lawThis law's good and bad points with enlarge the method of sections to be close; Is suitable reinforcement which is insufficient in the concrete structure component oblique section supporting capacity, or must exert the crosswise binding force to the compressional member the situation.7) Fang bolt anchor lawThis law is suitable in the concretes intensity rank is the C20~C60 concretes load-bearing member transformation, the reinforcement; It is not suitable for already the above structure which and the light quality structure makes decent seriously. 1.2The indirect reinforcement's general method1)Pre-stressed reinforcement law(1)Thepre-stressed horizontal tension bar reinforces concretes member in bending,because the pre-stressed and increases the exterior load the combined action, in the tension bar has the axial tension, this strength eccentric transmits on the component through the pole end anchor (, when tension bar and Liang board bottom surface close fitting, tension bar can look for tune together with component, this fashion has partial pressures to transmit directly for component bottom surface), has the eccentric compression function in the component, this function has overcome the bending moment which outside the part the load produces, reduced outside the load effect, thus sharpened component's anti-curved ability. At the same time, because the tension bar passes to component's pressure function, the component crack development can alleviate, the control, the oblique section anti-to cut the supporting capacity also along with it enhancement.As a result of the horizontal lifting stem's function, the original component's section stress characteristic by received bends turned the eccentric compression, therefore, after the reinforcement, component's supporting capacity was mainly decided in bends under the condition the original component's supporting capacity 。

第一课土木工程学土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。

他们也建造私有设施，比如飞机场，铁路，管线，摩天大楼，以及其他设计用作工业，商业和住宅途径的大型结构。

此外，土木工程师还规划设计及建造完整的城市和乡镇，并且最近一直在规划设计容纳设施齐全的社区的空间平台。

土木一词来源于拉丁文词“公民”。

在1782年，英国人John Smeaton为了把他的非军事工程工作区别于当时占优势地位的军事工程师的工作而采用的名词。

自从那时起，土木工程学被用于提及从事公共设施建设的工程师，尽管其包含的领域更为广阔。

领域。

因为包含范围太广，土木工程学又被细分为大量的技术专业。

不同类型的工程需要多种不同土木工程专业技术。

一个项目开始的时候，土木工程师要对场地进行测绘，定位有用的布置，如地下水水位，下水道，和电力线。

岩土工程专家则进行土力学试验以确定土壤能否承受工程荷载。

环境工程专家研究工程对当地的影响，包括对空气和地下水的可能污染，对当地动植物生活的影响，以及如何让工程设计满足政府针对环境保护的需要。

交通工程专家确定必需的不同种类设施以减轻由整个工程造成的对当地公路和其他交通网络的负担。

同时，结构工程专家利用初步数据对工程作详细规划，设计和说明。

从项目开始到结束，对这些土木工程专家的工作进行监督和调配的则是施工管理专家。

根据其他专家所提供的信息，施工管理专家计算材料和人工的数量和花费，所有工作的进度表，订购工作所需要的材料和设备，雇佣承包商和分包商，还要做些额外的监督工作以确保工程能按时按质完成。

贯穿任何给定项目，土木工程师都需要大量使用计算机。

计算机用于设计工程中使用的多数元件（即计算机辅助设计，或者CAD）并对其进行管理。

Civil EngineeringCivil engineering, the oldest of the engineering specialties, is the planning, design, construction, and management of the built environment. This environment includes all structures built according to scientific principles, from irrigation and drainage systems to rocket-launching facilities.土木工程学作为最老的工程技术学科，是指规划，设计，施工及对建筑环境的管理。

此处的环境包括建筑符合科学规范的所有结构，从灌溉和排水系统到火箭发射设施。

Civil engineers build roads, bridges, tunnels, dams, harbors, power plants, water and sewage systems, hospitals, schools, mass transit, and other public facilities essential to modern society and large population concentrations. They also build privately owned facilities such as airports, railroads, pipelines, skyscrapers, and other large structures designed for industrial, commercial, or residential use. In addition, civil engineers plan, design, and build complete cities and towns, and more recently have been planning and designing space platforms to house self-contained communities.土木工程师建造道路，桥梁，管道，大坝，海港，发电厂，给排水系统，医院，学校，公共交通和其他现代社会和大量人口集中地区的基础公共设施。