建立了考虑支座竖向变形以及上部结构转动时隔震结构的运动方程,研究了近场地震作用下结构高宽比和隔震结构周期对支座破坏形式的影响;提出了利用支座软碰撞和软提离防护支座在强烈近场地震作用下发生破坏的措施;对不同类型的橡胶缓冲挡块的力学性能进行了试验研究,并利用有限元软件对其进行了理论计算,给出了橡胶缓冲挡块的荷载一位移关系表达式;对具有软提离功能的支座,根据所需提离量的大小,设计了支座的具体构造.以某高层隔震结构的8度地震响应分析为例,验证了当支座具有软碰撞和软提离功能时,虽然支座的竖向位移有很多的增加,但支座所受的竖向拉压应力以及底层柱的剪力均有很大的减小.
The motion differential equations of base-isolated building were derived when the vertical displacement of rubber bearings and the rotation of the superstructure were considered. The effects of depth to width ratio and natural vibration period of the base-isolated building on the failure modes of the isolator were investigated. The soft pounding and soft up-lift function were suggested to prevent the bearings destroyed subjected to intense near-fault earthquake ground motions. The mechanical property of different types of the rubber bumpers were studied by the experimentation, and the load- displacement relation of these bumpers were calculated by finite element method. The specific struc- ture of rubber bearings with soft up-lift function was designed. Regarding a twelve-story reinforced concrete (RC) wall-frame isolation building as example, the seismic response of this building were an- alyzed. The study shows that if the isolated building has soft pounding and soft up-lift functions, tensile and compressive stresses of isolators are reduced greatly.