可液化地基-非规则截面地铁车站地震变形研究  

Seismic deformation characteristics of liquefaction soil-irregular section underground structure

作　　者：唐柏赞 李小军[2,3] 陈苏[3] 倪克闯[4] 景冰冰 TANG Baizan;LI Xiaojun;CHEN Su;NI Kechuang;JING Bingbing(School of Civil Engineering and Architecture,East China Jiaotong University,Nanchang 330013,China;College of Architecture and Civil Engineering,Beijing University of Technology,Beijing 100024,China;Institute of Geophysics,China Earthquake Administration,Beijing 100081,China;Institute of Foundation Engineering,China Academy of Building Research,Beijing 100013,China)

机构地区：[1]华东交通大学土木建筑学院,南昌330013 [2]北京工业大学建筑与土木学院,北京100024 [3]中国地震局地球物理研究所,北京100081 [4]中国建筑科学研究院地基基础研究所,北京100013

出　　处：《振动与冲击》2020年第11期217-225,共9页Journal of Vibration and Shock

基　　金：国家重点研发计划(2017YFC1500400);国家自然科学基金(51908216;U1839202;51778290);江西省教育厅科学技术研究项目(GJJ180339)。

摘　　要：以上层为五跨和下层为三跨的非规则截面地铁地下车站结构为原型,在可液化场地条件下进行土与地铁地下结构动力相互作用振动台试验。试验提出适用于液化地基-地下结构振动台模型试验的柔性传感链结合水沉法的模型地基制备方法,采用阵列式位移计测试了地基水平变形;分析了孔压发展、消散及空间分布规律,地震动强度与孔压关系,地表震陷与地基变形等。结果表明:饱和砂土振动孔压主要在地震过程中完成累积过程,振动孔压比与地震动Arias强度表现出显著的相关性;强震作用下地下结构存在改变了地基孔压空间分布模式;模型结构地震过程中出现了显著上浮现象,上浮不仅仅发生在孔压累积段,孔压消散段仍存在惯性上浮效应。随着液化区的扩展以及饱和砂土液化程度的增大,变截面地下结构不均匀沉降和倾斜现象显著,地下结构抗浮设计中应考虑截面结构形式差异性。Based on the prototype of an irregular section subway station with a five-span upper layer and three-span lower layer,a series of shaking table tests were performed to investigate the dynamic interaction of a liquefaction soil and an irregular section subway station.In this test,a model foundation preparation method based on flexible sensing chain combined with water sedimentation method was proposed,and the shape acceleration array was adapted to measure the horizontal deformation of the foundation.The development and spatial distribution of excess pore water pressure and the deformation of the model foundation were analyzed in the horizontal and vertical direction.The results show that excess pore water pressure is mainly accumulated in the process of earthquake,the excess pore water pressure ratio is significantly correlated with the Arias intensity,and its spatial distribution is changed by the underground structure.The remarkable floating of model structure occurs not only in the process of earthquake but also in the dissipation of excess pore water pressure.With the expansion of the liquefaction area and the increase of liquefaction degree of saturated sand,the uneven settlement and inclination of underground structure are clearly,the difference of section form should be considered in the anti-floating design of an underground structure.

关 键 词：液化地基 非规则截面地铁车站 振动台试验 振动孔压 地基变形 

分 类 号：TU354[建筑科学—结构工程] P315.9[天文地球—地震学]