考虑不均匀沉降的大跨网架结构地震反应分析  

Seismic response analysis of long-span grid structure considering uneven settlement

作　　者：颜学渊[1] 王秀珠[1] 

机构地区：[1]福州大学土木工程学院,福建福州350116

出　　处：《福州大学学报（自然科学版）》2017年第4期486-492,共7页Journal of Fuzhou University(Natural Science Edition)

基　　金：国家自然科学基金资助项目(51578160);福建省教育厅科技资助项目(JA15050);福建省高校杰出青年科研人才计划资助项目(810104)

摘　　要：针对不均匀沉降对大跨网架结构地震反应的不利影响,提出在柱顶设置不同隔震支座以减小不均匀沉降下结构的地震反应.建立大跨网架结构数值模型,进行模态分析,对比其动力特性.耦合不均匀沉降与地震作用,数值分析得到未发生不均匀沉降和发生不均匀沉降的三种结构在水平地震和竖向地震作用下的动力反应.结果表明,不均匀沉降导致结构发生内力重分布,使不同类型的杆件有大小不同的附加应力;不均匀沉降增大了网架结构的地震反应,也降低了隔震效果;三维隔震支座的竖向刚度较小,能够适应不均匀沉降带来的竖向变形,且对竖向地震作用的隔震效果显著,在发生不均匀沉降时仍具有一定隔震效果,而水平隔震支座则没有.A method of installing different isolation bearings on the top of the column was preset to re-duce the structural seismic response under uneven settlement, according to the negative influence of uneven settlement on the seismic response of long-span grid structure. Numerical models of long-span grid structures were established. Modal analyses of the aseismic grid structure, horizontal isolated grid structure and three-dimensional isolated grid structure were performed, their dynamic characteristics were analyzed and compared. Coupling uneven settlement and earthquake action,numerical analyses were performed,then horizontal and vertical seismic responses of the three structures were obtained. Analysis results indicate that uneven settlement causes inner force redistribution,makes different bars have different additional stresses. Uneven settlement amplifies the seismic reactions of the structures, and reduces the isolation effects. Three-dimensional isolation bearing has small vertical stiffness, it can adapt to the vertical displacement that uneven settlement brings about. It has vertical isolation effects for the vertical ground motions,even there is uneven settlement,while horizontal isolation bear-ing do not have.

关 键 词：不均匀沉降 大跨网架结构 水平地震作用 竖向地震作用 三维隔震 地震反应分析 

分 类 号：TU352.1[建筑科学—结构工程]