基础隔震建筑变刚度保护装置

Variable Stiffness Protection Device of Rubber Bearings in Seismic Isolated System

为了防止橡胶支座在低频激励下失稳破坏,按照多质点结构分析模型推导了不附加、右侧、左侧附加弹簧的运动方程及偏置方程,编制了相应的分析程序．通过在隔震层增设变刚度隔震保护装置作为第2道防线, 进行了5层框架的变刚度隔震保护模拟地震振动台试验．理论分析和试验结果表明,变刚度隔震保护装置能有效改变结构动力特性,减小隔震层的变形,使之限制在允许的范围内,从而防止了橡胶垫失稳破坏,同时还能使上部结构的层间剪力不明显增大．

This article deduced the equation of motion for non-affixation of spring, right affixation of spring and left affixation of spring on the basis of the multi-particle structural analytic model, and developed the computer program to prevent the failure of rubber bearing under low-frequency excitation. A shaking table test of a five-floor steel-frame model was completed successfully in Beijing University of Technology. The results showed that the variable stiffness isolated protection device can effectively reduce the horizontal deformation to prescribed limits, and can prevent the rubber bearings from failure because the dynamic character of the structure has been changed, and can make the interlayer shear forces in the super-structure increase slightly.