Tall Building Behavior
A reasonably accurate assessment of a proposed high-rise structure's behavior is necessary to form a properly representative model for analysis. A high-rise structure is essentially a vertical cantilever that is subjected to axial loading by gravity and to transverse loading by wind or earthquake.
为了合理地精确评价一个选定的高层建筑结构，必须建造一个能够正确反映其性能的模型。高层建筑结构基本上是一个竖向悬臂结构，轴向承受重力荷载作用，横向承受风和地震荷载作用。
Gravity live loading acts on the slabs, which transfer it horizontally to the vertical walls and columns through which it passes to the foundation. The magnitude of axial loading in the vertical components is estimated from the slab tributary areas, and its calculation is not usually considered to be a difficult problem. Horizontal loading exerts at each level of a building a shear, a moment, and some times, a torque, which have maximum values at the base of the structure that increase rapidly with the building's height. The response of a structure to horizontal loading, in having to carry the external shear, moment, and torque, is more complex than its first-order response to gravity loading. The recognition of the structure's behavior under horizontal loading and the formation of the corresponding model are usually the dominant problems of analysis. The principal criterion of a satisfactory model is that under horizontal loading it should deflect similarly to the prototype structure.
重力活荷载作用于楼板之上，楼板将其沿水平方向传递到竖向的墙和柱，最终传到基础。在竖向构件中，轴向荷载的大小取决于其所分配到的楼板面积大小，这种计算通常被认为是一个简单的问题。作用在建筑物每层间的水平荷载产生剪力、弯矩以及有时产生扭矩，这些值沿建筑高度向下迅速增大，在结构的基础处达到最大值。结构对水平荷载的反应表现在同时承担外部剪力、弯矩和扭矩作用，与结构对重力荷载的一阶响应相比要复杂得多。识别在水平荷载作用下结构的性能并形成相应的模型通常是结构分析的主要问题。一个正确模型的主要判断标准是在水平荷载作用下模型产生的变形应与原型结构产生的变形相似。
The resistance of the structure to the external moment is provided by flexure of the vertical components, and by their axial action acting as the chords of a vertical truss. The allocation of the external moment between the flexural and axial actions of the vertical components depends on the vertical shearing stiffness of the "web" system connecting the vertical components, that is, the girders, slabs, and bracing. The stiffer the shear connection, the larger the proportion of the external moment that is carried by axial forces in the vertical members, and the stiffer and more efficiently the structure behaves.
结构在抵抗外部弯矩时，其竖向构件受弯并且像竖向桁架弦杆那样受到轴向作用力。外部弯矩对竖向构件产生的弯曲和轴向作用是根据连接各竖向构件的“腹杆”系统竖向剪切刚度，即梁、 楼板和支承条件进行分配的。抗剪连接的刚度越大，竖向构件轴向力所承担的外部弯矩的比例就越大，因而结构的刚度和效率就越高。
The described flexural and axial actions of the vertical components and the shear action of the connecting members are interrelated, and their relative contributions define the fundamental characteristics of the structure. It is necessary in forming a model to assess the nature and degree of the vertical shear stiffness between the vertical components so that the resulting flexural and axially generated resisting moments will be apportioned properly.
上面所描述的竖向构件的弯曲和轴向作用与连接构件的剪切作用是相互联系的，他们之间的相互作用就确定了结构的基本特征。有必要建造一个模型来评价竖向构件的性质和这些竖向构件之间竖向剪切刚度的大小，以便将结构在弯曲和轴向受力时产生的抵抗弯矩进行正确的分配。
The horizontal shear at any level in a high-rise structure is resisted by shear in the vertical members and by the horizontal component of the axial force in any diagonal bracing at that level. If the model has been properly formed with respect to its moment resistance, the external shear will automatically be properly apportioned between the components.
作用于高层建筑结构的层间水平剪力是由竖向构件的抵抗剪力和各层间斜支撑构件轴向抗力的水平分力共同承担。如果建造的模型能够正确地满足抗弯要求，外部剪力自然会恰当地分配于各构件之间。
Torsion on a building is resisted mainly by shear in the vertical components, by the horizontal components of axial force in any diagonal bracing members, and by the shear and warping torque resistance of elevator, stair, and service shafts. If the individual bents, and vertical components with assigned torque constants, are correctly simulated and located in the model, and their horizontal shear connections are correctly modeled, their contribution to the torsional resistance of the structure will be correctly represented also.
作用于建筑上的扭矩主要是由竖向构件的抵抗剪力和各斜支撑构件轴向抗力的水平分力，电梯、楼梯、设备的井筒具有的剪切及弯扭抗力共同分担。如果在模型中，对每个具有抗扭能力的框架结构和竖向构件的模拟和所处位置的确定都是正确的，同时水平抗剪连接的形式也是正确的，则结构所表现出的抗扭能力也应该是正确的。
A structure's resistance to bending and torsion can be significantly influenced also by the vertical shearing action between connected orthogonal bents or walls. It is important therefore that this is properly included in the model by ensuring the vertical connections between orthogonal components.
交叉框架或剪力墙之间的竖向抗剪作用对一个结构的抗弯和抗扭能力能够产生很大的影响。因此，保证交叉构件之间的竖向连接并使其能正确地反映在模型中是非常重要的。
The preceding discussion of a high-rise structure's behavior has emphasized the importance of the role of the vertical shear interaction between the main vertical components in developing the structure's lateral load resistance. An additional mode of interaction between the vertical components, a horizontal force interaction, can also play a significant role in stiffening the structure, and this also should be recognized when forming the model. Horizontal force interaction occurs when a horizontally deflected system of vertical components with dissimilar lateral deflection characteristics, for example, a wall and a frame, is connected horizontally. In constraining the different vertical components to deflect similarly, the connecting links or slabs are subjected to horizontal interactive forces that redistribute the horizontal loading between the vertical components. For this reason, in a tall wall-frame structure the wall tends to restrain the frame near the base while the frame restrains the wall near the top. Similarly, horizontal force interaction occurs when a structure consisting of dissimilar vertical components twists. In constraining the different vertical components to displace about a center of rotation and to twist identically at each level, the connecting slabs are subjected to horizontal forces that redistribute the torque between the vertical components and increase the torque resistance of the structure.
在前面对高层建筑结构性能的讨论中，已经强调了在各主要竖向构件之同竖向剪切作用对结构抵抗水平荷载所具有的重要性。在各竖向构件之间还有另一种相互作用形式，即水平力相互作用也具有增大结构刚度的重要作用，应该在建造模型时认识到这一点。当各竖向构件发生水平位移时，由于侧向变形特征不同而引起水平力相互作用，例如水平相连接的框架和剪力墙。在强迫不同的竖向构件产生相同的水平位移过程中，连接杆件或楼板受到水平相互作用力，使各竖向构件承担的水平荷载重新分配。由于这种原因，在高层框架剪力墙结构中，在基础附近剪力墙约束了框架，而在建筑物顶部附近框架则约束了剪力墙。同样，由不相同的竖向构件组成的结构扭转时，也会产生水乎力相互作用。不同的竖向构件受到约束，围绕一个扭转中心在每层发生位移，产生相同的扭转，连接楼板受到水平力的作用使各竖向件之间的扭矩重新分配，增加结构的抗扭能力。
