Shaking-table tests on seismic behavior of subway station intersecting the ground fissure

Abstract

To investigate the seismic behavior of underground structures in the ground fissure site, a series of shaking-table tests on a subway station intersecting a ground fissure were carried out. Upon investigating the experimental phenomena and test results, propagation of earthquake waves through the soils with ground fissures was characterized and the damage mechanism of the subway station intersecting the ground fissure under earthquakes was studied. The results revealed that the features of wave propagation in soils with ground fissures were different from those in soils without ground fissures, in terms of the intensity, peak instant, and spectrum components. The movement of the subway station intersecting the ground fissure was better controlled by the surrounding soil with a lower input PGA. However, the response of the subway station and surrounding soil was not coordinated under strong earthquakes due to the ground fissure movement. The strain distribution for structural components was related to the position in the soil, and the strains of structural components were generally larger in the hanging-wall than those in the footwall, which was caused by the wave propagation in the ground fissure site. The damage mechanism of subway station intersecting the ground fissure was characterized by the cracks initially produced in the central columns and rapidly developed due to the coupling effect of the shear deformation, compression and bending moment. The bearing capacity of the central columns decreased rapidly, and then the bending moment and shear force at the connections between the slabs and side walls also exceeded the bearing capacity, resulting in the failure of the subway station.