加层隔震结构隔震支座参数优化及试验研究

Parameter optimization of isolator in structure with added floors and related shaking table tests

研究外套加层隔震体系在对老旧砌体房屋改造过程中铅芯叠层橡胶隔震支座(LRB)的参数优化配置问题,并对参数优化后结构的弹塑性进行数值分析和试验研究。选取隔震层的屈重比作为隔震支座的控制参数,建立模型分析隔震层在不同屈重比下结构的基底剪力和隔震层位移。分析表明加层隔震结构的隔震层存在一个最优的参数范围使得结构在地震作用下的响应最小,结构进入塑性后,仍能发挥较好的隔震效果。试验结果表明经参数优化的层间隔震结构随着地震输入幅值的增加,隔震层上部结构的调谐作用越强,其隔震效果越明显,当结构震损后隔震效应依然存在,但隔震效果小于未损伤的模型,与理论相符合。

The optimal parameter of lead laminated rubber bearings （LRBs） has been studied in the old masonry structure strengthened with external frames and added floors by using the middle story isolation technology.Elastoplastic analysis and shaking table tests are performed after the parameter for LRBs is optimized.The ratio of shear to weight in the isolation layer is selected as the control parameter of the isolator,and several models are established in order to analyze the base shear force of the structure and the displacement of the isolation floor with different isolator parameters.The results show that the response of the structure greatly reduces when the parameters of the isolation floor are selected in a certain range.The isolating effect is still good even after the structure is in the plastic stage.The shaking table tests show that the TMD effect of the superstructure is better with the increase of the earthquake input amplitude.The isolating effect still exists after the structure is damaged under the large earthquake,but it＇s not as good as the undamaged structure,which is in line with the theory.