钢筋混凝土低层框架结构易损性分析

Analyzing seismic fragility of typical low-rise RC frame buildings

按建筑结构抗震规范的规定构造加速度反应谱并将其作为随机激励,构造了四川地区典型公共钢筋混凝土框架结构有限元模型,采用拟动力时程方法对结构的抗震性能进行计算,得到了钢筋混凝土框架结构的易损性曲线.针对原型结构在地震作用下柱基础容易发生屈服破坏的情况,对原型结构基础采取了铅芯阻尼橡胶支座隔震加固措施,对加固后的框架结构进行了计算并得到了修正的易损性曲线.通过对比得到在地基不失稳的前提下,小震时结构发生中度以上损伤的概率非常小,大震时随着承重结构进入塑性屈服发生中度以上的损伤概率开始逐渐变大,而且钢筋混凝土框架结构纵横2个方向的易损性概率在大震时有差异,采取隔震加固措施后结构损伤概率明显减小.

A finite element analytical model was built in consideratjion of building history material difference and design configuration in Sichuan region＇ low-rise RC （reinforced concrete） frame buildings. Meantime a uniform response spectrum of accelerations has being set up based on China Seismic Code as input seismic excitation, dynamic time history method hadbeen using in computing the typical finite models and fragility curves been obtained. Furthermore lead-rubber bearings have be used on base of original building as building＇ strength procedure. Fragility curves of two kind of building are also be drawn after carefully analysis. Damage probabilities of sample buildings were very small dur- ing minor earthquakes and later amplify step by step with seismic intensity increasin. Moreover seismic fragility of sample buildings was obvious difference in major earthquake between longitudinal and lateral direction. Damage probability was decresed clearly after using seismic isolation produce.