大桥用英语说范文

大桥用英语说范文 THE MAIN PROBLEMS OF DOMESTIC BRIDGE DESIGNING Now, the countrys structural design process, such tendencies: more intensity considered in the design and durability consider less attention intensity limit to the use of state without limit state, and throughout the life cycle of the most important when it is precisely the use of performance; attention to the construction of the structure without attention to the maintenance of the structure. In fact, the current design of the bridge for more durability is a concern, as a concept, did not explicitly put forward the request of the use of life, nor the durability of specialized design. These tendencies to a certain extent, led to the current project aidents, the use of poor performance, the short life of the adverse consequences of structural engineering with the increasing emphasis on international durability, safety, contrary to the trend of applicability; does not conform to the structure dynamic and prehensive economy requirements. Bridge safety, durability, the main reason for poor 1) Construction and management of low level More bridges at home and abroad destruction and the sudden collapse of the bridge has been engineering more concerned about security issues. The general view is that the current project is barbaric incident management and construction caused by corruption. For the short term, such as the destruction and collapse of a sudden, mostly because of construction quality did not meet specifications and design requirements, typical problems include inadequate and construction materials intensity of failure; also exist, such as individual bridge jerry serious management issues, but also on bridge safety of the fatal damage. And a large number of bridges in the far did not achieve the expected life time, there has been affecting the normal use of disease and deterioration, especially in a number of bridges in use only a few years, or even just pleted soon on the serious problem of insufficient durability, which and the low quality of construction is an important relationship, the typical problems of inadequate protection of reinforced and the current widespread in the construction site of the serious problem of cracking ponent. These construction, although short-term deficiencies of the bridge will not be the normal use of a clear impact, but the long-term durability of the structure will have a very negative hazards. 2) Design theory and structure of the system is not perfect enough While acknowledging the existence of the problem, but it also, it is undeniable that bridge design fields, in particular on the bridge construction and use of the issue of safety there is still much improvement. Structural design first and foremost task is the choice of reasonable economic programmer, followed by the structural analysis and design of ponents and connections, and aess to regulate the safety factor specified or reliability of indicators to ensure the safety of the structure. Many designers often placent with norms on the structural strength of the safety of the need, and ignore the structural system, structure, structure, structure of materials, structure maintenance, as well as from the structural durability of the design and construction process to make use of that often appear in the man-made wrong areas to strengthen and guarantee the safety of the structure. Some structural integrity and ductility inadequate redundancy small, but some of Schema and the uncertainty of the line, causing partial excessive force; some concrete strength grade too low to protect slice through small diameter steel micromanage , a thin cross-section ponents of these structures have weakened the durability, it would seriously affect the safety of the structure. Many bridges, although the design specifications meet the requirements of the strength of only 5 to 10 years because of the durability of the problems affecting structural safety. Structural Durability shortage has bee one of the most realistic security issues, from design to construction and materials, such as angle of measures to strengthen the durability of the structure. Of the environment and the use of different conditions, different design of the structural system will target different aspects of the layout and structure requirements. Norms can not cover in detail the design staff should solve the various problems in the updated norms faster can also adapt to new understanding, new technologies, new materials, rapid development of the structure of the new requirements. Therefore, reasonable and reliable addition to the structures is designed to meet the requirements of norms, and to design a structure to the correct understanding of nature, rich experience and aurate judgments. And the need to improve efforts in the direction 1) Should pay more attention to the durability of structural problems Bridge in the construction and use of the process, will be subject to environmental, and the erosion of harmful chemical substances, and to bear vehicles, wind, earthquake, fatigue, overloading, human factors, such as external role, and bridge materials used by the self-degradation of performance will continue , resulting in the structure of the different degrees of damage and deterioration. In the field of long-span bridges, and from the country since the 1980s, the construction of a large number of cable-stayed bridge, although so far there collapse or serious damage to the few examples, but has more bridges because of the durability of cable to the problem advance for cable, and this not only affects the use of increased economic losses. Needs to be pointed out is that many of these problems and did not conduct a reasonable durability of the design, which has also prompted renewed awareness of durability of the bridge. Diseases are a lot of examples of that, in addition to construction materials and the reasons for a decisive impact on the durability of the structure from the structural factors (is design) flaws. From the country in the 1990s started to attach importance to the durability of the structure of the study, has also made quite a few suesses. Most of these studies and statistics from the analysis of the material point of view, on how to structure and design from the perspective of how and the design and construction staff to be readily aepted and operation of the bridge approach to improving the durability has been little research. Moreover, for a long time, people have always been emphasis on the methods of calculation on the structure; it ignores the details of the overall structure and processing concern. Design and durability of the structure of the structural design of a conventional nature of the difference between the current efforts will be needed on the durability of the qualitative analysis to the quantitative analysis of development. 2) Emphasis on the study of fatigue damage Bridge structure to withstand the vehicle load and wind load are dynamic load will be in a cycle of change within the structure of the stress, not only will cause the vibration of the structure, but also from the structure of the aumulated fatigue damage. The bridge is not used by the material is uniform and continuous, in fact there are many tiny flaws in the role of cyclic loading, these deficiencies will be progressive development of micro, a merger of injury, and gradually formed in the material macro cracks. If the crack is not effective macro-control, is very likely to cause material, the structure of brittle fracture. Early fatigue damage is not always easy to be detected, but the consequences are often disastrous. Fatigue damage has been considered in the design of steel bridge is the core issue of fatigue caused by the steel structure of steel crack more cases, many caused by fatigue fracture bridge collapse example. Over the past 20 years, fatigue injury research has entered the concrete structure, but by the use of corrosion of reinforced concrete structures dynamic performance and fatigue properties of need to be strengthened. On the fatigue damage of not only refers to the entire structure, the bridge structure often as a matter of fact some of the key parts of local fatigue failure of the entire structure and lead to failure, such as the cable-stayed bridge cables anchoring end of the fatigue damage. 3) Pay full attention to the problem of overloading the bridge There are three main vehicle overloading: One is the early construction of the old bridge overage load carriers and the other is the passage of vehicular traffic bridge over the original design; the other is illegal overloading of vehicles. The first two are the main reasons for the changes in the design load and the increase in the volume of traffic; users of the latter are illegal overloading of vehicles operating, the latter two phenomena of overloading in road transport in China is more mon. On the one hand, overloading the bridge may trigger fatigue. Overloading bridge would increase the rate of fatigue stress injury aggravated, or even some structural damage caused by overloading aidents. On the other hand, due to overloading of the bridge caused internal damage can not be restored, the bridge will be made of the work under normal load conditions change, which could endanger the safety of bridges and durability. For example, the concrete bridge has always been regarded as an adequate durability, but the overloading of the vehicle, cracking may our; cracks even in the load will be able to divest closed, but the internal structure of concrete has been damage, cracking ponent from the lower bend, Stiffness decline was in the normal use of load, should not have been cracking or structural cracks have bee smaller cracks in excess of the norms to allow a larger cracks or deformation. These will be used for structural performance and long-term durability has a negative impact, in addition to the Traffic Control departments should strengthen management, but also the need for overloading the consequences of research, analysis. 4) Actively learn from foreign experience and results Domestic bridge design the main problems is the use of the normal structure of poor performance (referring pared with the design expectations can be attributed to poor performance of the application, including the bridge too much vibration, linear irregularity, joints, diarrhea, excessive structural cracking and deformation, etc.), durability and safety of the poor (including short life span, high maintenance costs, and more frequent aidents, etc.). While these issues have with the current domestic construction quality and management level lower, but to be fair, since this situation can not be resolved in the short term, then as engineers we should address this issue in the premise, are fully taken into aount stage of construction and management and materials technology, the use of appropriate security, the appropriate way to ensure that the design of a bridge to the use of the performance, this is a more proactive and effective means. Especially the durability of the bridge and safety of many problems with the structure or the use of material selection are ueasonable and improper handling of the structural details. In European countries (such as Germany, Denmark, etc.), attached great importance to the structure of a performance-based design (PBD, Performance Based Design), which includes structural deformation, cracks, vibration, strong, handsome, durability, fatigue and so on. PBD study is to enable operators in the structure of the process, in addition to the guaranteed minimum security requirements; the idea of the use of performance should be good (including life and durability, corrosion resistance, fatigue resistance, aesthetics, etc.). By their very nature, the European countries PBD theory, research in the use of structure in the course of performance out of service, the performance by the weakening of the reasons for its ourrence and the mechanism of the law, to seek a new structural design concepts and methods. From the point of view of Europeans, PBD seems to be to the durability of the structure at the core of the prehensive use of performance indicators to Lesson 1 Careers in Civil Engineering (土木工程中的各种业务) 土木工程是一个意味着工程师必须要经过专门的大学教育的职业。许多政府管辖部门还有（一套）认证程序，这一程序要求工科毕业生在他们能积极地开始（从事）他们的事业之前，通过（认证）, 这种考试类似于律师职业里的律师考试一样。 大学里, 工科课程中着重强调数学、物理, 和化学,尤其在开始的二到三年。在工科所有分支中，数学非常重要, 因此它被着重地强调。今天, 数学包括统计学中的课程主要涉及集合, 分类, 和使用数字数据, 或信息。统计数学的一个重要方面是概率, 它涉及当有改变问题的结果的不同的因素, 或变量时，可能会发生什么。例如，在承担桥梁的建设之前, 运用统计研究来预计未来桥梁期望承受的交通量. 在桥梁的中，(各种)变量如作用在基础上的水压, 碰撞, 不同的风力的作用, 以及许多其它因素必须考虑。 由于在解决这些问题涉及大量的计算, 现在几乎所有工科课程中都包括计算机编程。当然,计算机能比人类以更快的速度和准确性解决许多问题。但如果不给计算机清楚和准确指令和信息，换句话说，一个好程序，它也是无用的。 虽然，在工科课程中，对技术科目着重强调，但当前的趋势还是要求学生学习社会科学和语言艺术的课程。工程和社会间的关系变得更加紧密; 因此,再一次充分说明, 工程师负责（承担）的工程在许多不同和重要的方面影响社会,这些方面是他们所知道的。并且，工程师需要一种很肯定（自信）语言表达方式来准备报告，这个报告要清楚明了，且在多数情况下, 是令人信服的。参与研究的工程师要能为科学出版物详细描述他们的发现。 最后两年的工科课程包括学生专业领域的学科。为准备使学生成为一名土木工程师, 这些专业课程可能会涉及诸如大地测量、土力学，或水力学。 学生在大学中的最后一年前常常就开始了频繁的工程师招聘。近年来，许多不同的公司和政府机构为争夺工程师而竞争。在今天这个重视科学技术的社会，受过技术训练的人当然是受欢迎的。年轻工程师也许选择进入环境或卫生工程领域工作, 例如, 在环境问题方面创造的许多机会; 或他们也许选择专门的高速公路工程的建筑公司; 或他们也许喜欢与政府机构当中处理水资源的机构之一共事。的确, 选择很多且多样。 当年轻工程师最后开始了真正的实践, 必须要运用到大学中学到的理论知识。最初，他 或她可能会被分配到与工程队合作。从而, 他们会得到在职的培训，这个培训将向管理人员证明他们将理论转化为实践的能力。 土木工程师可能在研究、设计、施工管理、养护或者甚至销售或管理单位工作。每一个工作领域都涉及不同的职责，不同的着重点以及运用不同的工程理论和经验。 研究是科学和工程实践的当中最重要的一个方面。研究员通常作为一个团队的成员与其它科学家和工程师一起合作。他或她经常受雇于政府或企业提供经费的实验室。与土木工程相关的研究领域包括土力学和土壤加固技术, 并且还包括新结构材料的开发和实验。 土木工程项目几乎是唯一（独一）的; 就是说，每个工程有它自己的难题和设计特点。所以, 在设计工作开始以前，要仔细的研究每个项目。研究包括勘测工程位置的地形和地基特点。它还包括考虑可能的比选, 譬如一个混凝土重力式坝或填土的土石坝。经济因素与在每个可能的比选方案有关，也必须斟酌。今天, 研究通常包括项目的环境影响的考虑。许多工程师, 通常在一起工作组成一个团队，这个团队包括测量员、土力学方面的专家和设计施工方面的专家，来参与制定这些可行性研究。 许多土木工程师在设计领域工作,他们中的许多人是这个行业的佼佼者。正如我们所见，土木工程师研究许多不同的结构, 因此工程师专门研究一类结构是通常的做法（一般的惯例）。在建筑设计中, 工程师经常作为建筑或结构公司的顾问。水坝、桥梁、给水系统, 和其它大项目通常；聘用几位系统工程师（总工程师） ，他们的工作是协助负责整个项目。在许多情况下, 也需要（涉及）其它学科的工程师。例如,在水坝项目中, 电子和机械工程师负责发电站及其设备的设计。在其它情况下, 土木工程师被分配到其它领域的项目上工作; 例如,在空间项目中, 需要土木工程师设计和施工诸如发射台和火箭存贮设施这样的结构。 在几乎所有土木工程项目中，施工是复杂的过程。它包括项目的进度安排和设备的使用以及材料，以便使得造价尽可能降低。必须考虑安全因素，因为施工很危险。许多土木工程师因此专门研究施工阶段。 Much of the work of civil engineers is carried on outdoors,often in rugged and difficult terrain or under dangerous conditions.Surveying is an outdoor oupation ,for example,and dams are often built in wild river valleys or gorges.Bridges,tunnels,and skyscrapers under construction can also be dangerous places to work.In addition,the work must also progress under all kinds of weather conditions.The prospective civil engineer should be aware of the physical demands that will be made on him or her. From:E.J Hall “The Language of Civil Engineering in English”,1984 Lesson 2 Modern Building and Structural Materials (现代建筑与建筑材料) 许多古代修建的大型建筑物现仍存在着，而且仍在使用。其中有罗马的万神庙和大圆形竞技场，伊斯坦布尔的圣索非亚教堂，法国和英国的哥特式教堂，和带有巨大的穹窿顶的文艺复兴式教堂，象佛罗伦萨的大教堂和罗马的圣彼得大教堂。它们都是些厚石墙的庞大建筑。这种厚石墙能抵抗建筑物本身巨大重量所形成的推力。 推力是建筑物各部分作用于其它部分的压力。 这些大型建筑物并非数学和物理知识的结晶。它们都是依据经验和观察而建造起来的，往往是反复试验出来的结果。它们能留存下来的原因之一是因为它们建造得强度很大多数情况下超出所需要的强度。可是古代的工程师也失败过。 例如在罗马，大部分人民都住在公寓中，这种公寓通常是一排排的有十层高的公寓大楼。其中有许多建造得很差，并且有时会倒塌，使许多人丧生。 但是，现在的工程师具备许多有利条件，不仅有经验资料，而且有科学数据供他预先做详细计算。一个现代工程师当他设计一座建筑物时，他要考虑这座建筑物所有组成材料的总重量，这就是所谓的静荷载，即建筑物自身的重量。他还必须考虑动荷载，即在建筑物投入使用时它要承受的人，车辆，设备、机器等等的重量。对于象桥梁这种需要承担高速汽车交通的构筑物，他必须考虑到冲力，即动荷载将借以作用于结构物的那种力。他还必须确定出安全系数，即附加的承载能力，以使建筑物的承载能力比上述三个因素结合起来还要强些。 现代工程师还必须了解建筑物所用材料经常承受的各种应力。其中包括压力和拉力这两种相反的力。在压力下，材料被压紧或推拢到一起，在拉力下，材料象一个橡皮筋那样被拉开或拉长。In the Fig.2.1,the top surface is concave,or bent inward,and the material in it is Intension.When a saw cuts easily through a piece of wood,the wood is in tension,but when the saw begins to bind,the wood is in pression because the fibers in it are being pushed tighter. 除了拉力和压力之外，还有一种称为剪力的力在起作用，我们给它下定义为，使材料沿应力线断裂的趋势。剪力可能发生在垂直面上，但它也可能沿着梁的水平轴线中性面 作用，中性面上既没有拉力也没有压力。 总的说来，有三种力作用于建筑物，垂直的那些向上或向下作用的力，水平的那些侧向作用的力，以及那些使建筑物发生旋转或转动的力。成一个角度作用的力是水平力和垂直力的合力。因为土木工程师设计的建筑物总是力求使它们静止或稳定，因此这些力必须保持平衡。例如，各垂直力必须波此相等。假如一个梁支承上面的一个荷载，梁本身必须有足够的强度去抗衡这个重量。水平力也必须彼此相等，才能不出现过多的向右或向左的推力。并且，那些可能使构筑物发生转动的力必须由向反方向推动的力去抵销。 现代最引人注目的工程事故之一1940年塔科马海峡大桥的倒塌，就是由于没有非常仔细地考虑这些因素中的最后一个因素。在一场暴风雨中，当每小时高达65公里的强劲狂风冲击这座桥时，狂风引起了沿着桥面方向的波动；同时还产生了一种使路面塌落的横向运动。幸亏工程师们从错误中汲取了教训，所以现在的通常做法是将按比例缩小的桥梁模型放在风洞中检验它们的空气动力学抵抗力。 早期的主要建筑材料是木材和圬工材料砖，石、或瓦，以及类似材料。砖行或砖层之间，用灰浆或沥青(一种象焦油的物质)，或者别的粘结剂粘结在一起。希腊人和罗马人有时还用铁条或铁夹子去加固建筑物。例如，雅典的帕提依神庙的圆柱上就有原来安装铁棍的钻孔，现在铁棍已经锈蚀竟尽。罗马人还使用一种叫白榴火山灰的天然水泥，这是用火山灰制成，在水中能变得和石头一样坚硬。 近代的两种最重要的建筑材料，钢材和水泥，都是十九世纪才采用的。直到那时为止，钢(基本上是铁和少量碳的合金)一直是要经过很复杂的工艺过程才能制成的，这就使钢只限于用在制剑刃这类特殊的用途上 。1856年发明贝色麦法以后，人们才能以低价大量地使用钢。钢的极大优点是它的抗拉强度，即：在特定程度拉力就象我们已经知道的那种会把许多种材料拉断的力的作用下，它的强度不会降低。新的合金进一步增强了钢的强度，并且还消除了它所存在的一些问题，如疲劳。疲劳是指在应力连续变化的情况下强度降低的趋势。 现代的水泥叫做波特兰水泥，是1824年发明的。是石灰石和粘土的混合物，将它加热，然后磨成粉末。在建筑现场或靠近现场的地方，将它掺上砂子、骨料(小石子、碎石或砾石)和水，就制成混凝土。不同的配料比例能制成不同强度和重量的混凝土。混凝土的适用性很强，它可以灌注，可以用泵抽送，甚至可喷注成各种各样的形状。而且，钢有很大的抗拉强 度，混凝土却有很大的抗压强度。因而，这两种材料可以互相补充。 它们还可以在其它方面互相补充：它们具有几乎相同的收缩率和膨胀率。因而它们可以在同时存在着压与拉力两种因素的情况下共同起作用。在受拉的混凝土梁或结构中埋置进钢筋，就制成钢筋混凝土。凝土和钢还形成一种很强的粘结力一种将它们连结起来的力使钢不能在混凝土中滑动。还有另一个优点就是钢在混凝土