Physical Modeling and Numerical Simulation of the Seismic Responses of Metro Tunnel near Active Ground Fissures

Abstract

Ground fissures pose serious hazards to underground, as well as aboveground, structures. In underground railways, which are near ground fissures, the potential for disasters is even higher since tunnels face threats from fissure activities. To determine the interaction between a tunnel and ground fissure in the event of an earthquake, field surveys and data analysis were applied to study the activity and damage caused by the fissure. Shaking table tests and a numerical simulation model were used to understand the dynamic response of the fissure site and tunnel. The fissure site had a clear hanging wall effect, where the acceleration amplification was larger in the hanging wall than that in the footwall both on the surface and at the middle of the fissure site. The zone of influence was also wider in the hanging wall. The acceleration magnification factor increased with the burial depth and peak acceleration of the input earthquake. The peak ground acceleration (PGA) decreased with the burial depth on both sides of the fissure. The greatest PGA coefficient was obtained at the surface of the site. The vertical soil pressure was influenced by the metro tunnel and fissure. The vertical soil pressure was larger in the hanging wall, especially in the zone near the fissure, but was less near the tunnel. The horizontal soil pressure above the tunnel was less than that near the fissure. The results of this study are essential for the safe design of underground railway systems.

Longitudinal Seismic Response of Metro Tunnels Crossing a Fault with Multi-Slip Surfaces

“…Many scholars have researched the mechanism behind damage to tunnel-crossing faults and achieved relevant results [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. For example, Mehdi Sabagh [14] conducted a 1:60 centrifuge test of a tunnel crossing an active normal fault, exploring the mechanism of tunnel failure and the process of crack development.…”

“…Yang-Zhihua et al [17] concluded that seismic motion and faults can change the initial stress field of the tunnel surrounding rock, resulting in stress accumulation and stress concentration in the tunnel surrounding rock near the fault and, ultimately, progressive destruction. Liu-Nina et al [18] carried out shaking table model tests for a metro tunnel crossing active ground cracks. They studied the acceleration response, soil pressure, and strain variation of the metro tunnel under seismic action.…”

“…Buildings 2024, 14, x FOR PEER REVIEW 2 of 18 near the fault and, ultimately, progressive destruction. Liu-Nina et al [18] carried out shaking table model tests for a metro tunnel crossing active ground cracks. They studied the acceleration response, soil pressure, and strain variation of the metro tunnel under seismic action.…”

Possible mechanism of the formation of the Jichechang ground fissure in Datong, China, based on in-situ observations

“…The formation of GFs is usually related to the effects of internal and external forces and human activity (Peng 2012;Lu et al 2013;Liu et al 2019b). As a geological disaster, GFs not only cause serious damage to various types of engineering structures, such as urban buildings, roads, bridges, and underground pipelines (Peng et al 2018;Liu et al 2019a), but also cause many environmental problems including groundwater system damage and the destruction of land (Howard and Zhou 2019). Because GF disasters are common in many countries worldwide, such as the United States, Saudi Arabia, and Mexico, GF formation mechanism and the factors affecting their development have received research attention (e.g., Jachens and Holzer 1982;Holzer 1984Holzer , 1991Bankher and Al-Harthi 1999;Wang et al 2009Wang et al , 2016Pacheco-Martínez et al 2013).…”