高层隔震结构非平稳随机地震响应与动力可靠度分析  

Non-stationary random response and dynamic reliability of high-rise seismic isolated structure

作　　者：孙臻[1] 王曙光[1] 王赟玉[1] 刘伟庆[1] 

机构地区：[1]南京工业大学土木工程学院,江苏南京210009

出　　处：《建筑结构学报》2011年第12期210-216,共7页Journal of Building Structures

基　　金：国家自然科学基金重大研究计划项目(90815017);国家自然科学基金项目(50908115);建设部专题项目(建质防函[2007]109号)

摘　　要：考虑地震动的非平稳特性,运用虚拟激励法对高层隔震结构在非平稳激励下的随机地震响应进行研究。采用Bouc-Wen模型与刚度退化的Bouc-Wen模型分别模拟隔震层与上部楼层的滞变特性,建立高层隔震结构的非线性化运动方程。运用精细积分法对每一时刻的响应进行求解,得到高层隔震结构在非平稳地震激励下各楼层响应的时变方差。基于首次穿越准则,研究非平稳随机地震激励下各楼层与结构整体的可靠度。运用上述理论,分析某高层基础隔震结构在8度与9度罕遇地震作用下的随机地震响应,隔震后上部结构各楼层层间位移方差较非隔震结构大幅减小。研究表明:结构的位移响应呈现强烈的非平稳性,且具有明显的时滞现象;高层隔震结构在强震作用下各楼层可靠度较非隔震结构有很大的提高,说明高层隔震结构具有足够的安全性。运用可靠度理论进行分析亦能发现结构的薄弱部位,该方法对结构的性能设计与性态控制具有指导意义。Considering the non-stationary characteristics of the earthquake ground motion,the random seismic response of high-rise seismic isolated building is investigated using pseudo excitation method.The Bouc-Wen model and the stiffness degradation of Bouc-Wen model are used to simulate the hysteresis of the isolation layer and the upper structure,respectively.The nonlinear motion equation of the high-rise seismic isolation structure is established.And the system response for each moment is solved by precise integration method.The time-history response of each floor under non-stationary earthquake excitation is got.Based on the first passage criterion,the reliability index of each floor and the whole structure are calculated.Those theories are used to analyze random earthquake response of a high-rise base isolated structure under 8 and 9 degree rare earthquakes.The time-history variance of story displacements of the seismic isolated system substantially reduced,which is compared with the non-isolation system.The structural displacement responses have a strong non-stationarity and a significant time lag phenomenon.It is also found that the reliability index of each floor and the whole structure are significantly larger compared with that of traditional aseismic structures under rare earthquakes.It is proved that the high-rise seismic isolated structure has adequate security.The weak floor of the structure can be found by using the reliability theory.This method is instructive for structural performance design and state control.

关 键 词：高层隔震结构 BOUC-WEN模型 非平稳随机响应 虚拟激励法 动力可靠度 

分 类 号：TU352.1[建筑科学—结构工程] TU973.31