高层建筑结构三维抗震设计

Three-Dimensionai Aseismic Design of Tall Buildings

本文参照我国现行《工业与民用建筑抗震设计规范》,讨论了三维坐标系下高层建筑结构地震设计荷载的选取。采用地震惯性力逐层传递求得结构各楼层地震剪力和扭矩,由振子广义位移幅值和备振型的乘积直接给出地震荷载下各振型结构楼层的相对位移。本文方法不仅节省机时、概念清楚,而且为高阶振型对结构各楼层影响的研究提供了有效的依据。此外,还提出按振子能量比选取振型及振型组合所需振型个数和选择合适振型组合法的方法,并在几个算例中均取得较为满意的结果。

Referring to the current Aseismic Design Code for Industrial and Civil Buildings, the selection of earthquake actions used in three-dimensional analysis of tall buildings has been discussed. In this paper,the seismic shear and torsion are obtained by the transfer of inertia force due to earthquakes story by story and the relative drifts for different vibration modes can be computed 'directly from the product of the generalized displacement amplitude of vibrator and the vibration mode. In comparing with the conventional methods used through electronic computer, this method has the merits of saving computing time, having a clear concept, and providing basis for studying the effects of high-order vibration modes on each story of the structure. Besides, the way of selecting vibration modes,the number of modes required in combination, and the suitable way of combining vibration modes according to energy ratio for each vibrator are also presented. The results obtained by the given method are in good agreement with those of the numerical examples worked out in ref.[3], [6] and [7].