隔震层屈服系数对基础隔震结构性能的影响

为研究隔震层屈服系数对采用橡胶隔震支座的基础隔震多层结构水平向地震反应的影响，首先对单质点体系在不同屈服系数下的地震反应规律进行分析，包括按等效线性化反应谱法简化计算和按时程分析法计算。然后以一个多层隔震结构为例，研究多质点体系在不同屈服系数下的地震反应规律。同时,分析在不同支座压应力和地震输入强度下的相关性。分析结果表明：对应最小水平向减震系数，存在一个最优隔震层屈服系数区间，且隔震支座平均压应力越小，最优屈服系数越大;隔震层水平位移随隔震层屈服系数的增加而减小;隔震层和各楼层最小水平向减震系数对应的最优屈服系数不同;随着隔震层屈服系数的增加，上部各楼层的水平加速度也相应增加，表现为中间层增幅小、顶层和隔震层增幅大。水平地震输入峰值加速度越大，最小水平向减震系数对应的隔震层最优屈服系数越大，建议参考罕遇地震作用下的地震反应评估隔震装置的隔震效果。

Influence of yield coefficient of isolation layer on performance of base isolation structures

The influence of yield coefficient of isolation layer on the horizontal seismic response of multistory structures with rubber isolation bearings was studied in this paper. Firstly, the seismic response of SDOF systems with different yield coefficients were studied, where the equivalent linearization spectrum method and the time-history method were considered. Then, the seismic response of MDOF systems with different yield coefficients was studied by taking a multistory isolation structure as an example. At the same time, the correlation under different compression stresses of rubber bearings and seismic input intensities was analyzed. The results show that: there is an optimal yield coefficient range of the isolation layer for the minimum horizontal seismic reduction factor; the smaller the average compressive stress of rubber bearings, the larger the optimal yield coefficient; the horizontal displacement of the isolation layer decreases with the increase of the yield coefficient; the optimal yield coefficient for achieving minimum horizontal seismic reduction coefficient of the isolation layer and that of each floor is different. With the increase of the yield coefficient of the isolation layer, the acceleration of the upper floors increases correspondingly, with the smallest increase for the middle floors, and larger increases for the top floor and the isolation layer. The larger the horizontal acceleration of the earthquake input, the larger the optimal yield coefficient of the isolation layer with the minimum horizontal seismic reduction factor. It is suggested to evaluate the isolation effect of the isolation device referring to the seismic response of the severe earthquake.