实验技术与管理2025，Vol.42Issue(5)：97-104,8.DOI:10.16791/j.cnki.sjg.2025.05.012
主余震序列荷载作用下地铁车站离心机振动台模型实验设计
Design of centrifuge shaking table model test for subway station subjected to mainshock-aftershock sequence
摘要
Abstract
[Objective]The existing research on the seismic response of underground structures and seismic design codes mainly focuses on the impact of a single earthquake.However,in reality,most earthquake disasters are accompanied by aftershocks.After the mainshock,the structure may suffer substantial damage,and the potential destructive effects of aftershocks on the structure must not be overlooked.Meanwhile,subway stations,essential for urban public transportation,have strict requirements for seismic fortification.Therefore,their seismic response under the action of the mainshock-aftershock sequence must be evaluated.[Methods]This study presents a centrifuge shaking table model test of a subway station under the mainshock-aftershock action.According to the similarity theory,the similarity relationships of various physical quantities were derived at a model scaling ratio of 1:60.The site was prepared using Fujian standard sand with a relative density of 60%.Saturated sand and dry sand sites were set up separately.Because a horizontal unidirectional shaking table was used,30%steel sand was added to the site above the model to simulate the inertial force of the overlying soil under vertical seismic motion.The site was equipped with accelerometers,laser displacement sensors,and pore water pressure sensors.The single-story,single-span subway station structure was made of microparticle concrete,and strain gauges were arranged at the positions of columns,slabs,and side walls.The Darfield seismic wave was selected,and the wavelet transform method was adopted to ensure the target response spectrum met the specification requirements.A sequence of seismic motions containing one mainshock and two aftershocks using the repetition method was constructed.The dynamic characteristics of the mainshock-aftershock sequence were the same,with a relative magnitude for peak acceleration of 0.85.A 30-second time interval and a 30-second amplitude of 0.05 g white noise were set between each stage of the earthquake.[Results](1)After the mainshock,the ground surface settlement of saturated sand soil sites was slightly greater than that of dry sand sites.Under the continuous action of multiple aftershocks,the surface subsidence of dry sand sites was greater.(2)When seismic waves propagated upward from the bottom in a saturated sand field,they exhibited a decreasing trend.In contrast,dry sand fields had a greater amplification effect on seismic acceleration.(3)Strain developed at both ends of the middle column in subway stations under earthquake action.Aftershocks can continuously increase the residual strain in the structure.(4)The sudden change in strain observed during the second aftershock and the sustained increase in residual strain corresponded to the shear failure at the top of the middle column and the fracture at the bottom.[Conclusions]The excitation of the aftershock caused multiple cracks in the top slab and severe shear failure at the end of the middle column.Because of the lack of deformation coordination ability,the middle column was a vulnerable member in the seismic performance of the subway station.Compared with saturated sand sites,surface subsidence and damage to subway station structures are more severe in dry sand sites.Liquefaction may hinder the propagation of seismic shear waves and weaken the dynamic response of station structures.The results provide a theoretical basis for the seismic design of subway station structures and enrich the study of soil dynamics.关键词
离心机振动台/地铁车站/主余震序列/地震响应/模型实验Key words
centrifuge shaking table/subway station/mainshock-aftershock sequence/seismic response/model test分类
建筑与水利引用本文复制引用
袁丽,崔振东,张隆基,王苏扬,任国锋..主余震序列荷载作用下地铁车站离心机振动台模型实验设计[J].实验技术与管理,2025,42(5):97-104,8.基金项目
国家自然科学基金面上项目(52378381) （52378381）
江苏省力学教育教学研究一般课题(2021jslxjy210) （2021jslxjy210）
中国矿业大学教改项目独立重点课题(2022DLZD01) （2022DLZD01）
