横向非一致激励下土层地震响应的振动台模型试验研究  

Shaking table test study on seismic response of free-field soil under transverse non-uniform seismic excitations

作　　者：赵密[1] 万宁潭 韩俊艳[1] 李立云[1] 侯本伟[1] 杜修力[1] ZHAO Mi;WAN Ningtan;HAN Junyan;LI Liyun;HOU Benwei;DU Xiuli(Key Laboratory of Urban Security and Disaster Engineering of Ministry of Education,Beijng University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学城市与工程安全减灾教育部重点实验室

出　　处：《地震工程与工程振动》2019年第2期57-68,共12页Earthquake Engineering and Engineering Dynamics

基　　金：国家自然科学基金创新研究群体(51421005);国家973计划项目课题(2015CB057902);国家青年科学基金项目(51808018);北京市科技计划课题(Z181100009018001);北京市青年科学基金项目(8184062)~~

摘　　要：针对自由场土体的非线性地震响应问题,采用悬挂式连续体模型箱,开展了横向一致激励和非一致激励下砂土自由场土体的振动台试验。通过试验,研究了不同地震动、不同地震强度作用下自由场土体的地震动反应特性及其变化规律,包括场地土体的动力特性、加速度地震响应、剪应力-剪应变以及土体的沉降。研究结果表明:土体的非线性发展程度不仅与地震动记录有关,还与地震动输入方式、加载等级有关;与一致激励相比,非一致激励下土体运动的不一致性引起了更强的土体结构性变化,频率降低,阻尼比增大,土体的加速度峰值和频谱峰值均有降低,土体的非线性发展相对较快。土体剪应力-剪应变曲线和沉降曲线的变化规律一定程度上也反映了土体的塑性发展情况,所得结论和自由场地震反应宏观现象一致,彼此佐证了结论的合理性。The shaking table test of the sand soil free field under lateral uniform and non-uniform excitation is carried out to investigate the nonlinear seismic response of free field soil, By using a suspended continuum model box. Through experiments, the ground motion response characteristics and variation of free-field soil under different earthquake motions and different seismic intensity are studied,including the dynamic characteristics of soil, acceleration peak magnification coefficient, shear stress-shear strain and soil settlement.The results show that the degree of non-linear development of soil is not only related to the record of ground motion, but also to the input mode and loading grade of ground motion. Compared with the uniform excitation, Inconsistent movement of free-field soil under the non-uniform excitation lead tostronger structural change of soil, the decrease of frequency, the increase of damping ratio, the reducing of soil acceleration peak and spectral peak value and the relatively fast nonlinear development of soil.The variation law of soil shear stress shear strain curve and settlementcurve also reflected the plasticity development of soil.The conclusions obtained are consistent with the macroscopic phenomena of the free-field seismic response, which corroborated each other's rationality.

关 键 词：非一致激励 振动台试验 地震响应 土体非线性 

分 类 号：TU457[建筑科学—岩土工程]