摘要
当地下结构穿越液化土层,场地液化可能会对结构的动力响应产生影响。基于已开展的局部液化夹层场地地下结构离心机振动台模型试验,建立二维局部液化场地土-结构动力相互作用的有限元模型。计算模型考虑砂土液化后易产生剪切大变形的特点以及饱和两相介质与结构接触的非线性特性,通过与试验结果对比,验证数值模型的正确性,进一步分析土-结构接触非线性特性对结构地震响应的影响。研究结果表明:孔压的增长是由于地震作用的累积效应;近场砂土由于土结相互作用的存在超孔压比上升的更快,且由于土与结构变形不协调而更易消散;对于局部液化夹层场地,土结捆绑接触会放大结构的地震响应,随着地震动强度的增大,砂土层液化程度提高,场地非线性特性增强,土结刚度差异增大,土结界面采用捆绑接触所带来的误差越大,故应合理考虑土结界面接触非线性问题。
When an underground structure crosses the liquefiable soil layer,the site liquefaction may have an adverse effect on the dynamic response of the structure.A two-dimensional finite element model of the soil-structure dynamic interaction at a local liquefiable interlayer site was established using centrifuge shaking table test platform.The calculation model accounts the significant shear deformation of sand during liquefaction,as well as the nonlinear properties of the interface between the saturated two-phase medium and structure.To ensure the accuracy of the numerical model,the numerical results are compared to the experimental data.In addition,the influence of soil-structure interface on structural seismic response was analyzed.The results show that the increase in pore pressure is due to the cumulative effect of seismic action.Due to soil interactions,the excess pore pressure in the near-field rises faster than in the far-field,and it dissipates faster due to the inconsistency in the soil and structural deformation.For local liquefiable interlayer sites,binding soil-structure interface will amplify the seismic response of the structure.The larger the intensity of ground motion,the greater the liquefaction of the saturated sand and the nonlinear properties of the site.Furthermore,the greater the difference in stiffness of soil and structure and the bigger the inaccuracy produced by the binding contact of the soil interface.The study suggests to consider the nonlinear problems of soil-structure interface for local liquefiable interlayer sites.
作者
闫冠宇
许成顺
张梓鸿
宋佳
豆鹏飞
YAN Guanyu;XU Chengshun;ZHANG Zihong;SONG Jia;DOU Pengfei(Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China;School of Civil Engineering,North China University of Technology,Beijing 100144,China;Department of Hydraulic Engineering,Tsinghua University,Beijing 100084,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2023年第S01期3643-3653,共11页
Chinese Journal of Rock Mechanics and Engineering
基金
国家重点研发计划项目(2018YFC1504305)
国家自然科学基金青年面上项目(52078020)
北京市自然科学基金面上项目(8192012)
关键词
土力学
液化场地
离心机振动台试验
土-结界面模型
有限元分析
soil mechanics
liquefiable site
centrifuge test
soil structure interface model
finite element analysis
作者简介
闫冠宇(1996-),女,2017年毕业于哈尔滨理工大学土木工程专业,现为博士研究生,主要从事地下结构抗震方面的研究工作。E-mail:yanguanyu@emails.bjut.edu.cn;通讯作者:许成顺(1977-),女,现任教授。E-mail:xuchengshun@bjut.edu.cn
