A hierarchical approach to soil arching problem via physical model test with photoelastic measurement and discrete element simulations

抄録

Soil arching is a unique phenomenon in which soil grains plays an active role in efficiently resisting external load. A traditional trapdoor problem was investigated via a physical model test using bi-dimensional particles made of PTFE elastomer. Each particle was coated by trimmed thin photoelastic sheet such that force transmission can be visualized and their contact forces can be measured. A hierarchical approach for expanding the model size was taken. We attempted the discrete element method (DEM) to simulate existing photoelastic tests, from which microscopic model parameters for DEM were calibrated. The area of the trapdoor problem can easily be enlarged in the discrete element simulations, which overcomes practical limitation in physical model tests. The comparison of the results from the experiment and simulation reveals that the initial condition of the assembly prepared for the DEM is too perfect to reflect the local perturbation in the contact distribution that can be naturally expected in the experiment. Numerically enlarged discrete element models has successfully captured the general patterns of contact force distribution due to the soil arching.