多点地震输入对高层大跨度连体结构动力响应的影响

Influence of multipoint seismic input on dynamic response of highrise large-span connected structure

利用动力有限元法推求了多点地震动输入时带连廊高层结构的简化地震动力反应计算公式,并编制了Newmark-β方法的数值求解软件。分析与计算结果表明,考虑多点地震动输入时,连体结构顶部最大水平位移及竖向位移变化很小,固端弯矩值及固端轴力值增加也很少;构件截面抗弯刚度越大,则其内力也越大;连廊高度增大时,局部固端弯矩值减小,但局部固端轴力值增大。当连廊长度不超过60m时,结构设计计算仍可按一致地震动输入考虑。

A nmultiply inputumerical model was established for seismic dynamic response of large-span connected structure underearthquake waves. It started from dynamic finite element method. The software for its numerical so-lution was presented with Newmark-β method. Computation results show that under multiply input earthquakewaves, both the horizontal and vertical displacements at structural top experience little varitions and so the mometand axial force at fixed ends are. The internal forces increased with cross-section flexural rigidity. The local ben-ding moment decreases with increase of hight of connecting gallery, but the local axial forces increases with it,which means the increase of global bending moment. The consistent input method for earthquake waves should stillbe effective if the length of connecting gallery is less than 60m.