基础隔震建筑中应用变刚度保护装置的地震反应分析

长周期的地面运动会使隔震建筑物发生类共振而导致隔震支座失稳破坏。在这种情况下,可以利用附加的弹簧改变建筑物的周期,减小隔震层的变形,使之限制在允许的范围内,同时使上部结构的层间剪力不明显增大。按照多质点结构分析模型推导了不发生附加、右侧附加、左侧附加弹簧的运动方程,编制了相应的分析程序。通过对模型实例分析,论证了变刚度保护装置在限制支座大变形中的作用,讨论了在工程设计中如何选取变刚度保护装置的适宜参数。

SEISMIC RESPONSE ANALYSIS OF ISOLATED PROTECTION DEVICE WITH VARIABLE-STIFFNESS FOR BASE-ISOLATED BUILDINGS

If the displacement of rubber bearing of base-isolated buildings, which is usually caused by some what resonance effect from long period ground motion, the additional stiffness components will work together with rubber bearings and then the possibility of further increase of the displacement of rubber bearing is suppressed and reaches the prescribed limitation because the natural period of the base isolation building has been changed. However the extra stiffness would let the story shear forces of the super-structure slightly increase. A muhi-particle structural analytic model is set up. The motion equations of three states of non-affixation, right affixation and left affixation are deduced, and the computer program is developed. On the basis of exemplary analysis for typical base-isolated building, the effectiveness of the device in limitation of developing large lateral displacement of rubber bearing is demonstrated and the way of choosing appropriate parameters for the protective device is discussed.