近断层地震动下基础隔震弹簧限位对结构响应影响试验研究

摘要

近断层地震动作用下,基础隔震结构隔震层可能会产生大位移,限位装置能起到限制隔震层位移的作用,但与隔震层上部结构发生软碰撞,会对上部结构响应造成影响.对9种弹簧限位基础隔震振动台模型试验数据进行分析,结果表明:9种工况均取得良好限位效果;但碰撞会激发结构的高阶振型,在碰撞时刻隔震层会产生速度的突然增大;限位碰撞可导致上部结构的层间位移和加速度响应增大,但合理设计限位器的刚度和预留距离可减小上部结构响应.%The large deformation of a base isolation layer could be induced by near-fault ground motions.Although the displacement-constraint devices can constrain the large displacements of the base isolation layer,impacts between the displacement-constraint devices and the superstructures of the base isolation layer may change the dynamic responses of the superstructures.9 sets of test data about base-isolated structures impacting on spring displacement-constraint devices were analyzed.The results indicate that the displacement-constraint devices can constrain the displacement of the base isolation layer well,but higher modes will be exicited and great velocity increments may be produced due to the impact.The story drifts and accelerations of superstructures will increase in the case of impact.The responses of superstructures may be reduced when the stiffness of the displacement-constraint devices and the gaps between the devices and structures are designed reasonably.