Collapse modeling of a subway station structure in seismic subsidence site under strong mainshock-aftershock sequences

TY - JOUR

T1 - Collapse modeling of a subway station structure in seismic subsidence site under strong mainshock-aftershock sequences

AU - Zhang, Zhongliang

AU - Cui, Zhen-Dong

AU - He, Pengpeng

AU - Zhao, Chenyang

AU - Pak, Ronald Y.S.

PY - 2025/11

Y1 - 2025/11

N2 - When strong earthquakes occur, the mainshock can trigger aftershocks in a short period, causing additional damage to structures. However, the complex dynamic characteristics of seismic subsidence site make this problem more challenging. This study uses numerical simulations to reproduce the collapse process of a shallow-buried subway station in seismic subsidence site under strong mainshock-aftershock sequences, focusing on the effects of mainshock and aftershock intensity on the seismic response of the site and subway station structure. The results indicate that the mainshock dominates the seismic response of both the soil site and subway station structure, while aftershocks lead to secondary damage or even collapse of the structure. A notable observation was the relative uplift of the subway station within the soil, reaching up to 18%. The presence of the subway station significantly altered the stress state and subsidence of surrounding soils. Under strong mainshock-aftershock sequences, the damage ratio with a damage factor exceeding 0.9 of the subway station section is over 30%. Additionally, a four-parameter model is proposed to predict the maximum inter-story drift of subway station structures under mainshock aftershock sequences. This research aims to guide the seismic design and post-earthquake rescue efforts for subway stations in urban soft soil areas.

AB - When strong earthquakes occur, the mainshock can trigger aftershocks in a short period, causing additional damage to structures. However, the complex dynamic characteristics of seismic subsidence site make this problem more challenging. This study uses numerical simulations to reproduce the collapse process of a shallow-buried subway station in seismic subsidence site under strong mainshock-aftershock sequences, focusing on the effects of mainshock and aftershock intensity on the seismic response of the site and subway station structure. The results indicate that the mainshock dominates the seismic response of both the soil site and subway station structure, while aftershocks lead to secondary damage or even collapse of the structure. A notable observation was the relative uplift of the subway station within the soil, reaching up to 18%. The presence of the subway station significantly altered the stress state and subsidence of surrounding soils. Under strong mainshock-aftershock sequences, the damage ratio with a damage factor exceeding 0.9 of the subway station section is over 30%. Additionally, a four-parameter model is proposed to predict the maximum inter-story drift of subway station structures under mainshock aftershock sequences. This research aims to guide the seismic design and post-earthquake rescue efforts for subway stations in urban soft soil areas.

KW - Aftershock

KW - Subway station

KW - Seismic subsidence

KW - Uplift

KW - Damage ratio

U2 - 10.1016/j.compgeo.2025.107478

DO - 10.1016/j.compgeo.2025.107478

M3 - Article

SN - 0266-352X

VL - 187

JO - Computers and Geotechnics

JF - Computers and Geotechnics

M1 - 107478

ER -