近断层滑冲效应脉冲地震动对场地液化的影响  

Effect of near-fault pulse-like ground motion with fling-step on site liquefaction

作　　者：董文悝 高广运[1] 宋健[3] 薛帅 DONG Wen-kui;GAO Guang-yun;SONG Jian;XUE Shuai(Department of Geotechnical,Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education Engineering,Tongji University,Shanghai 200092,China;School of Civil and Environmental Engineering,University of Technology Sydney,Sydney NSW 2007,Australia;College of Civil and Transportation Engineering, Hohai University,Nanjing 210098,China;Imperial College London,London SW7 2AZ,England)

机构地区：[1]同济大学地下建筑与工程系岩土及地下工程教育部重点实验室,上海200092 [2]悉尼科技大学土木与环境工程学院 [3]河海大学土木与交通学院,江苏南京210098 [4]帝国理工学院

出　　处：《浙江大学学报（工学版）》2018年第9期1651-1657,共7页Journal of Zhejiang University：Engineering Science

基　　金：国家自然科学基金资助项目(41372271)

摘　　要：利用开源有限元平台OpenSees,建立一个20 m长的土柱模拟自由场地的地震响应.通过分析近断层滑冲效应脉冲地震动作用下场地产生的变形、应力,结合其地震动持时,衡量滑冲效应脉冲地震动对场地液化的影响.研究表明,滑冲效应脉冲地震动由于其独特的脉冲特性,较无脉冲地震动使土柱产生更大的孔隙水压力比、循环应力比,相应的等效循环周数值也较大,这三方面共同增大了场地发生液化的可能性.滑冲效应脉冲地震动产生的高孔压持续时间较短,使液化后的变形量较小.A soil column of 20 m was established to simulate the seismic responses of free site by using the open source finite element software OpenSees.Then the influence of fling-step effect on site liquefaction was evaluated by the stress and strain induced in the soil column,coupling with the collected ground motion duration of each simulation.Results show that the ground motion with fling-step effect is more likely to induce larger pore water pressure ratio and cycle stress ratio than non-pulse ground motions due to its special pulse characteristics.Besides,the ground motion with fling-step effect could generate higher number of equivalent cycles in comparison to the nonpulse motions.All these factors increase the occurrence of site liquefaction and cause a larger permanent vertical deformation.However,the ground motion with fling-step effect induced high pore pressure duration is relatively limited,which is detrimental to the liquefaction deformation.

关 键 词：滑冲效应 脉冲地震动 场地液化 大变形 地震动持时 

分 类 号：TU434[建筑科学—岩土工程]