基于可液化场地离心机振动台试验的地下结构地震响应研究  

Seismic responses of underground structures based on centrifuge shaking table test in liquefiable site

作　　者：张梓鸿 闫冠宇 许成顺[2] 杜贺港 ZHANG Zihong;YAN Guanyu;XU Chengshun;DU Hegang(China Academy of Railway Sciences Corporation Limited,Urban Rail Transit Center of CARS,Beijing 100081,China;Key Laboratory of Urban Security and Disaster Engineering,Ministry of Education,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]中国铁道科学研究院集团有限公司城市轨道交通中心,北京100081 [2]北京工业大学城市与工程安全减灾教育部重点实验室,北京100124

出　　处：《岩土工程学报》2025年第2期324-336,共13页Chinese Journal of Geotechnical Engineering

基　　金：国家杰出青年科学基金项目(52225807);国家自然科学基金面上项目(52078020)。

摘　　要：为研究场地液化对地下结构地震响应的影响,开展了可液化场地条件下的离心机振动台试验,得到液化场地地下结构地震响应规律,并通过Pushover分析方法确定场地不同液化程度下土体刚度的衰减程度。研究结论如下:在4种加载工况下,模型结构的侧墙及顶板总应变峰值响应完全处于弹性范围内,中柱应变在大震作用下略超过混凝土的弹性应变限值,损伤程度较低,模型结构表现出良好的抗震性能;四种加载工况下,可液化场地中结构层间位移较结构等高处场地层间位移衰减了63%~76%;由场地水平位移和土-结构体系位移衰减比来看,尽管饱和砂土层液化后会出现较大的水平位移,但场地液化后土-结构刚度比降低仍会避免结构出现较大的层间位移和严重破坏;在实际工程应用Pushover分析方法对液化场地地下结构进行简化分析时,可考虑最不利工况,将土体模量折减为初始模量的3%进行计算。In order to study the effects of site liquefaction on the seismic responses of underground structures,the centrifuge shaking table tests under liquefiable site conditions are carried out.The seismic response laws of underground structures in liquefiable site are obtained.The attenuation degree of soil stiffness under different liquefaction degrees of the site is obtained by using the Pushover analysis method.The conclusions are drawn as follows:(1)The peak total strain responses of the sidewalls and plates of the model structures are within the elastic range under the four loading conditions.The strains of the center column just exceed the elastic strain limit of concrete under large earthquakes,with a low level of damage.The underground structures conforming to the existing codes exhibit good seismic performance.(2)The inter-story drifts of the structures in the liquefiable site are attenuated by 63%~76%compared with those in the site at the structural equivalent height under the four loading conditions.(3)From the horizontal displacement of the site and the displacement attenuation ratio of the soil-structure system,although the liquefaction of the saturated sandy soil layer will lead to a larger horizontal displacement of the site,the reduction of the soil-structure stiffness ratio caused by the liquefaction of the site will still avoid the structures from experiencing a larger inter-story drift and serious damage.(4)When applying the Pushover analysis method to simplify the analysis of underground structures in liquefiable sites,the most unfavorable conditions should be considered,and the soil modulus can be discounted to 3%of the initial modulus for calculation.

关 键 词：地下结构 地震响应 可液化场地 离心机振动台试验 

分 类 号：TU433[建筑科学—岩土工程]