Tall Building Structure
Tall towers and buildings have fascinated mankind from the beginning of civilization, their construction being initially for defense and subsequently for ecclesiastical purposes. The growth in modern tall building construction, however, which began in the 1880s, has been largely for commercial and residential purposes.
人类从文明社会的开始就向往着高楼大厦，最初建造的高大建筑是为了自身安全，随后发展到教会建筑。现代高层建筑的发展始于19世纪80年代，主要是用于商业和住宅。
Tall commercial buildings are primarily a response to the demand by business activities to be as close to each other, and to the city center, as possible, thereby putting intense pressure on the available land space. Also, because they form distinctive landmarks, tall commercial buildings are frequently developed in city centers as prestige symbols for corporate organizations. Further, the business and tourist community, with its increasing mobility, has fuelled a need for more, frequently high-rise, city center hotel accommodations.
由于商业活动的距离要尽可能小，并且都尽可能地位于城市中心，因此使城市中心可以利用的土地面积严重短缺，这是兴建高层建筑的主要原因。此外，高层商业建筑还成为具有特色的地标，它们作为企业机构声望的象征竖立在城市的中心。此外，随着商业和旅游业活动的增加，需要在城市中心地区建造更多的高层宾馆以提供住宿。
The rapid growth of the urban population and the consequent pressure on limited space have considerably influenced city residential development. The high cost of land, the desire to avoid a continuous urban sprawl, and the need to preserve important agricultural production have all contributed to drive residential buildings upward. In some cities, for example, Hong Kong and Rio de Janeiro, local topographical restrictions make tall buildings the only feasible solution for housing needs.
迅速增长的城市人口和随之减少的有限的可以利用的土地已经在相当大的程度上影响了城市住宅的发展。土地价格的昂贵，不希望城市产生过度的扩展，必须保护重要的农业生产等，所有这些要求都促使住宅建筑向高层发展。在一些城市中，例如香港和里约热内卢，由于土地面积紧缺，高层建筑是解决住房需求的唯一途径。
Ideally, in the early stages of planning a building, the entire design team, including the architect, structural engineer, and services engineer, should collaborate to agree on a form of structure to satisfy their respective requirements of function, safety and serviceability, and servicing. A compromise between conflicting demands will be almost inevitable. In all but the very tallest structures, however, the structural arrangement will be subservient to the architectural requirements of space arrangement and aesthetics.
在最初的建筑设计阶段，理想的做法是包括建筑、结构和维护工程师的整个设计组协同工作，确定一个能满足各专业功能要求的、安全的、维护保养方便的结构形式。在两种不同的意见中，一般采用折中的办法。除了非常高的高层结构，高层建筑的结构布置常常服从于建筑平面布置和美感的要求。
The two primary types of vertical load-resisting elements of tall buildings are columns and walls, the latter acting either independently as shear walls or in assemblies as shear wall cores. The building function will lead naturally to the provision of walls to divide and enclose space, and; of cores to contain and convey services such as elevators. Columns will be provided, in otherwise unsupported regions, to transmit gravity loads and, in some types of structure, horizontal loads also.
高层建筑有两种基本构件起承担竖向荷载的作用，这就是柱和墙，后者在独立起作用时为剪力墙，汇集成一体起作用时为剪力墙筒体。建筑的功能需要很自然地要求采用墙对空间进行分隔和封闭，以及形成筒体并安装电梯等类服务性设施。柱通常用于在没有其他支撑的区域内传递重力荷载，在有些结构类型中也传递水平荷载。
The inevitable primary function of the structural elements is to resist the gravity loading from the weight of the building and its contents. Since the loading on different floors tends to be similar, the weight of the floor system per unit floor area is approximately constant, regardless of the building height. Because the gravity load on the columns increases down the height of a building, the weight of columns per unit area increases approximately linearly with the building height.
结构构件必然具有的首要功能是抵抗由建筑物自重和它所承担的重量所形成的重力荷载。由于各楼层重力荷载大致相似，所以，各层楼板的单位面积重量近似为一个常量与建筑物的高度无关。因为作用于柱的重力荷载沿建筑物的高度越向下越大，所以柱在单位面积上增加的荷载与建筑物的高度近似为线性关系。
The highly probable second function of the vertical structural elements is to resist also the parasitic load caused by wind and possibly earthquakes, whose magnitudes will be obtained from National Building Codes or wind tunnel studies. The bending moments on the building caused by these lateral forces increase with at least the square of the height, and their effects will become progressively more important as the building height increases.
竖向结构构件最可能具有的第二功能是抵抗由风和地震引起的附加荷载，这些荷载值的大小可以从国家建筑规范或者风洞研究中获得。在建筑物上由这些水平荷载引起的弯矩至少是高度的平方，因此，它们的影响将随建筑物高度的增加变得更加重要。
Once the functional layout of the structure has been decided, the design process generally follows a well-defined iterative procedure. Preliminary calculations for member sizes are usually based on gravity loading augmented by an arbitrary increment to account for wind forces. The cross-sectional areas of the vertical members will be based on the accumulated loadings from their associated tributary areas, with reductions to account for the probability that not all floors will be subjected simultaneously to their maximum live loading. The initial sizes of beams and slabs are normally based on moments and shears obtained from some simple method of gravity load analysis, or from codified mid- and end-span values.
当结构形式按功能要求确定后，设计步骤通常按照常规的重复过程进行。构件尺寸的初步计算一般是在重力荷载的基础上再加上一个考虑风荷载的增量。竖向构件的截面确定是在与其有关的所属面积上的累积荷载的基础上按荷载产生的概率进行折减，这是因为并非所有楼面都同时承受最大活荷载的作用。梁和板的最初尺寸通常是通过简化的重力荷载分析方法，或者通过从规范中查出中跨和边跨的数值，求得的弯矩和剪力来确定的。
A check is then made on the maximum horizontal deflection, and the forces in the major structural members, using some rapid approximate analysis technique. If the deflection is excessive, or some of the members are inadequate, adjustments are made to the member sizes or the structural arrangement. If certain members attract excessive loads, the engineer may reduce their stiffness to redistribute the load to less heavily stressed components. The procedure of preliminary analysis, checking, and adjustment is repeated until a satisfactory solution is obtained.
然后，采用快速近似的分析技术，检验主要结构构件的最大水平位移和受力情况。如果位移过大或某些构件不合适，应调整构件尺寸或结构布置。如果某些构件负担的荷载过大，可以降低这些构件的刚度，使荷载重新分配到承受应力较低的构件上。重复进行上述初步分析、检验、调整的过程直至得出满意的结果。
Invariably, alterations to the initial layout of the building will be required as the client's and architect's ideas of the building evolve. This will call for structural modifications, or perhaps a radical rearrangement, which necessitates a complete review of the structural design. The various preliminary stages may therefore have to be repeated a number of times before a final solution is reached.
初步方案完成后，业主和建筑师通常会提出修改意见。这就需要对结构进行改进，有时可能需要完全重新设计，这需要对整个结构设计进行审查。以上各初步设计步骤在取得最终的结果之前总是要重复很多次。
Speed of erection is a vital factor in obtaining a return on the investment involved in such large-scale projects. Most tall buildings are constructed in congested city sites, with difficult access; therefore careful planning and organization of the construction sequence become essential. The story-to-story uniformity of most multistory buildings encourages construction through repetitive operations and prefabrication techniques. Progress in the ability to build tall has gone hand in hand with the development of more efficient equipment and improved methods of construction.
在这种大规模的工程项目中，施工速度是影响投资收益率的重要因素。大多数高层建筑都是建造在拥挤的市区内。交通困难，因此施工进度的详细计划和组织是非常重要的。大多数多层建筑物结构相同的层可通过重复操作和工厂预制技术来提高施工速度。高层建筑施工的先进性还取决于研制更有效的设备和改进施工方法。
