考虑铅芯橡胶隔震支座力学性能退化的基础隔震结构地震作用研究  

Study on seismic action of base isolation structure considering mechanical performance degradation of lead rubber bearings

作　　者：刘彦辉[1,2] 蒋婷婷 钟伟健 周福霖[1,2] 谭平[1,2] Liu Yanhui;Jiang Tingting;Zhong Weijian;Zhou Fulin;Tan Ping(Earthquake Engineering Research&Test Center(EERTC),Guangzhou University,Guangzhou 510006,China;Key Laboratory of Earthquake Resistance and Absorption Engineering&Structure Safety of the Ministry of Education,Guangzhou University,Guangzhou 510006,China;Xi’an University of Architecture and Technology,Xi’an 710055,China)

机构地区：[1]广州大学工程抗震研究中心,广东广州510006 [2]广州大学工程抗震减震与结构安全教育部重点实验室,广东广州510006 [3]西安建筑科技大学,陕西西安710055

出　　处：《土木工程学报》2022年第8期46-54,共9页China Civil Engineering Journal

基　　金：国家重点研发项目(2021YEE0112200);国家自然科学基金(51778163)。

摘　　要：针对铅芯橡胶隔震支座在长周期长持时地震作用下由于铅芯温度上升发生力学性能退化的问题,通过压剪设备对铅芯橡胶隔震支座进行了快速水平往复力学性能试验,研究其在快速往复加载下水平剪切力学性能的变化。试验结果表明,铅芯橡胶隔震支座在快速往复荷载作用下,随着加载次数的增多,其特征强度显著下降,且前期下降的幅度比后期大,屈服后刚度在加载过程中变化较为平缓。然后基于试验结果,采用改良的广义Bouc-Wen模型,提出了铅芯橡胶隔震支座在快速水平荷载下力学性能退化的力学模型,然后基于铅芯橡胶隔震支座性能退化的力学模型,对一实际隔震结构进行仿真,研究该结构在长周期长持时地震作用下的动力响应。仿真结果表明考虑支座退化效应得到的隔震层位移和层间位移角不仅比不考虑支座退化效应得到的大,且最大值已超出设计允许范围,因此在基础隔震设计时建议要考虑铅芯橡胶隔震支座在长周期长持时地震作用下力学性能退化情况。In view of the problem that the mechanical properties of lead rubber bearings may degenerate due to fast temperature rise during long cycle,the mechanical performance tests on the lead rubber bearings were carried out using compression shear equipment,and the changes of various mechanical properties of the bearings under rapid reciprocating loading were studied qualitatively and quantitatively.The test results showed that for lead rubber bearing under rapid reciprocating loading,its characteristic strength may decrease significantly with the number of loads,but the decrease magnitude in the early stage is larger than that in the later stage.The stiffness of the bearing after yielding tends to be gentle during the loading process.Based on test results and the modified generalized Bouc-Wen model,the mechanical model for degeneration of the mechanical performance of the bearing under rapid reciprocating loading is proposed.Furthermore,the derived model was applied to finite element simulation of the actual structure in order to study the long-term dynamic response of this structure.Simulation results showed that the seismic displacement of isolation layer and story drift are not only larger than those without considering the degradation effect of bearing,but the maximum value shall also be beyond the design allowable range.Hence,it is necessary to consider the degradation of lead rubber bearings under the long-period and long-duration seismic actions in the seismic design.

关 键 词：长周期长持时地震动 铅芯橡胶隔震支座 特征强度 恢复力模型 地震响应 

分 类 号：TU352.12[建筑科学—结构工程]