土木工程专业英语lesson 2 Introduction to Structural Design

Structural Design
Armed with this information， the structural designer can then select the appropriate cross section． Before any analysis，however， a decision must be made on the building material to be used： it will usually be reinforced concrete， structural steel， or both． Ideally， alternate designs should be prepared with each ．
Structural Design
Ideally， the engineer and architect will collaborate throughout the design process so that the project is completed in an efficient manner． In effect， however， the design can be summed up as follows: The architect decides how the building should look： the engineer must make sure that it doesn’t fall down． Although this is an oversimplification， it affirms the first priority of the structural engineer： safety．
参考译文
serviceability [,sə:visə'biliti] n. 可用性，适用性； 使用可靠性；[计] 可服务性；可维修性
其他要考虑的主要因素包括适用性 （如何合理表 现结构的外观和偏差）和节约。一个经济的建筑 需要高效使用材料和施工工时。虽然这通常通过 需要最少建材的设计来实现， 但往往节约可通过 使用稍多的建材而产生一个更简单、更易于施工 的项目来实现。
参考译文
evaluation [i,vælju'eiʃən] n. 评价；[审计] 评估；估价； 求值
Bending moment [力] 弯矩；[力] 弯曲力矩； [力] 挠矩
一个好的设计需要对多个设计规划评估 — — 构 件及其连接的不同组合。换句话说，应准备几种 备用设计及其成本比较。 对每个设计规划，都必 须审查其单独组件设计。这就要求有建筑框架的 结构分析和各个构件的力与弯矩的计算。
参考译文
fixture ['fikstʃə] n. 设备；固定装置；固定于某处不 9;tiʃən] n. 划分，分开；[数] 分割；隔墙； 隔离物
vt. [数] 分割；分隔；区分 Dead load 恒载；静负荷 Live load 动荷；活负载；有效负载
作用于结构上的力被称为荷载。所有荷载分 属于两大类别： 恒载与活载。恒载是那些永久的 负荷，包括结构本身的重量，有时也称为自重。 建筑物内的其他恒载包括某些非结构构件的重量 ，诸如地板、 有灯具的吊顶、 隔断等。
Loads
All of the loads mentioned thus far are forces due to gravity and are referred to as gravity loads, live loads，which can also be gravity loads， are those that are not as permanent as dead loads．This type may or may not be acting on the structure at any given time，and the location may not be fixed．
参考译文
collaborate [kə'læbəreit] vi. 合作；勾结，通敌 oversimplification ['əuvə,simplifi'keiʃən] n. 过度单纯 化；过分简单化
理想情况下，工程师和建筑师将在整个设计过 程中合作，以便以有效的方式完成项目。不管 怎样，实际上设计可以概括如下： 建筑师决定 建筑物的外观： 工程师必须确保它不会倒。虽 然这是过于简单化，但它阐明了结构工程师的 第一要务： 安全。
参考译文迄今为止所提到的所有负荷均源于重力故称之为重力荷载活荷载也可以是重力荷载是那些不像恒载那样永久的荷载
LESSON 2
Introduction to Structural Design
Structural Design
The structural design of buildings， whether of structural steel or reinforced concrete, requires the determination of the overall proportions and dimensions of the supporting framework and the selection of the cross sections of individual members． In most cases the functional design， including the establishment of the number of stories and the floor plan， will have been done by an architect， and the structural engineer must work within the constraints imposed by this design．
Loads
If the live load is applied slowly and is not removed and reapplied an excessive number of times. the structure can be analyzed as if the loads were static. If the load is applied suddenly, as would be the case when the structure supports a moving crane. we must account for the effects of impact. If the load is applied and removed many times over the life of the structure. fatigue stress becomes a problem. and we must account for its effects. Impact loading occurs in relatively few buildings, notably industrial buildings, and fatigue loading is rare, with thousands of load cycles over the life of the structure required before fatigue becomes a problem．
Structural Design
Other important considerations include serviceability (how well the structure performs in terms of appearance and deflection) and economy． An economical structure requires an efficient use of materials and construction labor ． Although this can usually be accomplished by a design that requires a minimum amount of material， savings can often be realized by using slightly more material if it results in a simpler， more easily constructed project．
参考译文
be referred to as
被称为…
迄今为止所提到的所有负荷均源于重力，故称之 为重力荷载，活荷载也可以是重力荷载，是那些 不像恒载那样永久的荷载。这种类型的荷载可能 会在任何给定时间作用于结构，也可能不会 ； 其作用位置也可能不固定。
Loads
Examples of live load include furniture， equipment, and occupants of buildings． In general， the magnitude of a live load is not as well defined as that of a dead load， and it usually must be estimated． In many cases， a given structural member must be investigated for various positions of the live load so that a potential failure situation is not overlooked．
参考译文
occupants ['ɔkju:pənts] n. 居住者；购买者；租赁 人（occupant的复数）
活荷载的例子包括家具、 设备和建筑物的住客。 一般情况下，活荷载的大小无法像恒载那样定义 ，通常必须估计。在许多情况下，必须对给定的 结构构件进行处在不同活载作用位置时的检验， 使潜在的破坏不被忽视。
Structural Design
A good design requires the evaluation of several framing plans--that is， different arrangements of members and their connections． In other words， several alternate designs should be prepared and their costs compared． For each framing plan investigated， the individual components must be designed． This requires the structural analysis of the frame(s) of the building and the computation of forces and bending moments in the individual members．
参考译文
有了这些信息，结构设计者则可以选择适当 的横截面。不过，在任何分析之前必须决定要使 用的建筑材料 ： 通常是钢筋混凝土、 钢结构或 兼有。理想情况下， 每个方案都应准备不同的设 计。
Loads
The forces that act on a structure are called loads．They belong to one of two broad categories：dead load and live load． Dead loads are those that are permanent， including the weight of the structure itself， which is sometimes called the self-weight． Other dead loads in a building include the weight of nonstructural components such as floor coverings， suspended ceilings with light fixtures， and partitions．
参考译文
framework ['freimwə:k] n. 框架，骨架；结构，构架
constraint [kən'streint] n. 约束；强制；局促，态度
不自然
impose [im'pəuz]
vi. 欺骗；利用；施加影响
vt. 强加；以…欺骗；征税
无论钢结构或钢筋混凝土，建筑物的结构设 计需要确定整体比例，支持框架尺寸和选择各个 构件截面。在大多数情况下，包括确定楼层的数 目和平面图的功能设计， 将由建筑师和结构工程 师依据这一设计的限定条件来完成。