DEM study on evolution of soil arching in a deep trapdoor in seismic shaking conditions

Abstract

In this study, the soil arching formed in a deep trapdoor model was investigated using the discrete element method, considering the magnitude, frequency, and direction in seismic shaking conditions. The parameters were validated using prior trapdoor test results. The results showed that the ultimate soil- arching ratio increased after shaking, indicating that the soil arching effect had degraded. The fluctuation range of the soil arching ratio increased with increasing shaking frequency. The ultimate average coordination number of the region above the trapdoor steadily increased as the shaking magnitude increased. Soil arching was more significantly influenced by shaking in the vertical (z-axis) direction than in the horizontal direction. The force chain in the arched region above the trapdoor progressively increased as the shaking magnitude increased, and clearly degenerated above the stationary region. As the shaking amplitude increased, the ultimate soil arching ratio increased; however, the ultimate coordination number decreased.