隔震支座下支墩转动对隔震结构的影响分析

Influence analysis of rotation of lower pier under isolation bearing on isolated structure

隔震分析中,通常假定隔震支座下支墩刚度足够大且与大地刚接,而实际下支墩因自身变形及地基基础的变形会发生转动。当二者变形引起的转动过大时,对隔震结构的影响不容忽视。分析了隔震支座下支墩转动对隔震结构的影响,并提出了通过折减系数对隔震支座水平等效刚度进行计算。结果表明:隔震支座下支墩转动会减小隔震支座水平等效刚度,其折减系数随着隔震支座水平等效刚度及下支墩高度的增大而减小。

In the analysis of isolation,it is usually assumed that the rigidity of the lower pier under the isolation bearing is large enough and rigid connected with the earth,but in fact,the lower pier will rotate due to its own deformation and the deformation of the foundation.When the rotation caused by the two deformations is too large,the influence on the isolated structure cannot be ignored.The influence of the rotation of the lower pier under the isolation bearing on the isolation structure was analyzed,and it was proposed to calculate the horizontal equivalent stiffness of the isolation bearing through the reduction coefficient.The results show that the rotation of the lower pier of the isolation bearing will reduce the horizontal equivalent stiffness of the isolation bearing,and the reduction coefficient will decrease with the increase of the horizontal equivalent stiffness of the isolation bearing and the height of the lower pier.