超高层建筑地震反应中高阶振型影响分析

建立了上海中心大厦的三维精细化有限元模型,针对上海地区场地类别选用了7条地震波作为水平输入,采用振型叠加的时程分析法计算了结构地震反应。通过对不同数量振型组合计算所得结构反应的比较分析了上海中心大厦地震反应中高阶振型的影响,结果表明:高阶振型对上海中心大厦结构的最大水平位移和最大层间位移角影响不大,对结构地震内力的影响不容忽视,为研究超高层建筑结构抗震设计中振型组合数目的选取提供了参考依据。

INFLUENCE OF HIGH MODES OF SUPER HIGH-RISE BUILDING ON ITS SEISMIC RESPONSES

A 3D fine finite element model of Shanghai Center Tower is established and used to analyze the seismic responses of the structure by applying the modal superposition method in time domain.According to the soil site condition in Shanghai region,seven seismic waves are selected as horizontal inputs.The influence of high-order modes on the seismic responses of the structure is studied,based on the comparison among the numerical results of the seismic responses,obtained from superposition calculations with different number of the structural modes.The result show that the influence to the structural maximum horizontal displacement and maximum angle of relative storey displacement is not obvious,but the influence to the internal force of the structure cannot be ignored.This research provides the reference for choosing the reasonable modal number in superposition calculation of the super high-rise building seismic design.