针对高层混凝土框架和框架剪力墙基础隔震结构,考虑水平双分量记录的4种不同输入方法(在水平面内按原地震记录最大幅值对应方向重新分解获得新的双分量记录,地震输入时将此两记录各自幅值较大分量分别对应结构较柔及较强方向),展开弹塑性时程分析对比,进行损伤及耗能评价。建立适用性更广的综合损伤指标,并建议以周期延长系数作为评价隔震效果的指标。研究表明:地震记录不同分解下的输入对能量反应影响不大,对损伤结果有一定影响;输入分解得到幅值最大的分量时结构损伤不一定最严重、耗能也不一定最大。框剪结构隔震效果较好,但滞回耗能在楼层分布上底层耗能突出,而框架结构滞回耗能沿楼层基本呈梯形分布特征。结构能量反应的时程变化特性主要受输入地震记录控制,与Arias强度曲线接近。
To evaluate the extent of damage and level of energy dissipation of high-rise RC base isolation structures with moment resisting frame system(MRFS) and shear-wall frame system(SWFS),nonlinear inelastic time history response analysis was carried out under horizontal dual-component earthquake input.Four types of earthquake input were derived when dual components were switched for two records,the original record and a new record obtained from decomposition of the original record in the direction of the maximum amplitude.A potentially useful damage index was established,and an index of performance evaluation of base-isolation was proposed as the period-enhancement factor.Results show that varying decomposition-angle of the original record has little influence on energy response,but appreciable on damage distribution,and that input of the new record might not correspond to the most serious damage and the largest energy dissipation.For the SWFS,the first story has the largest energy dissipation compared with other stories,while the MRFS exhibits better energy-dissipation and a near-trapezoid distribution.Generally,structural energy response is mainly influenced by the input record,with similar trend as the Arias intensity curve.