Numerical simulation of gravel deposits using multi-circle granule model

This study proposes a new Multi-Circle Granule Model (MCGM), based on overlapping circles with various diameters to create an irregular particle shape, to simulate the geometry-dependent behavior of gravel particles for two-dimensional mechanical analyses of gravel deposits. The MCGM model is implemented in a Distinct Element Method (DEM) program for numerical simulation. Two numerical examples are presented to study the effects of gravel shapes on the angles of repose in free falling tests, and on the stability of gravel tunnel excavation in trap door tests. Additionally, the numerical study reveals that the shapes of gravel significantly affect the angle of repose. Furthermore, interlocking, anisotropy, and contact numbers among the Gravels are found to be key factors governing the stability of gravel tunnel excavation. These numerical simulation results of geometry-dependent behavior are quite encouraging for the MCGM model.