Earth fissures pose a significant risk to the seismic safety of underground structures at earth fissure sites (USEFs), particularly for large-scale underground frame structures such as subway stations. To date, the failure mechanism of USEFs has only been analyzed qualitatively and requires further comprehensive investigation. Moreover, the existing failure prediction methods for USEFs are complicated, challenging to execute, time-consuming, and incur significant financial costs, necessitating the establishment of a simple and efficient failure prediction method. This study conducted a shaking table test on a USEF to investigate the dynamic response of earth fissure sites and the seismic damage characteristics of a USEF. Based on the experimental results, a tailored pushover analysis method was developed to predict the seismic failure of the USEF and was applied to reveal its underlying seismic failure mechanisms. It was found that low-frequency ground motions are significantly amplified at the earth fissure site and that the acceleration amplitudes at the hanging wall and footwall are nonuniform. This nonuniform acceleration leads to significant extrusion and separation between the hanging wall and footwall. The extrusion causes the soil to rise, exerting additional axial pressure and bending moments on the lateral resistance members. These additional forces lead to uneven internal force distributions within the USEF, highlighting that structurally weak members are prone to failure and accelerating structural damage. The bottom column at the hanging wall is the critical seismic member of the USEF, which requires focused reinforcement and monitoring to increase resilience. The tailored pushover analysis method accurately represents the deformation characteristics at earth fissure sites. The method captures distinct structural destruction patterns, enhancing its utility in seismic failure prediction for USEFs.

来源平台：TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY