Multiscale Modelling and Analysis of Soil Arching in Granular Soils

Understanding the ground response induced by underground excavation in granular soils is important for assessing the construction risk in similar urban geological environment. This paper presents an application of the hierarchical FEM/DEM coupling multiscale approach in the simulation of classical trapdoor tests. The multiscale simulation reveals the development pattern of the soil deformation, soil shear zones, and load transfer in the case of various overburden depths and soil density. Furthermore, the multiscale approach provides insight into the microstructure evolution underlying the macroscopic deformation from the perspective of RVE powered by DEM. This study demonstrates that the multiscale approach can bypass the phenomenological assumptions on conventional constitutive relations and accurately reproduce the soil arching behavior due to underground loss. Meanwhile, based on the efficiency advantage of massively parallel computation, the multiscale approach is expected to further solve the engineering-scale problems under complex boundaries.