Granular Assembly Simulation for Ground Collapse

Using Cundall's simulation method, the present work aims at study in the mechanism of slope collapse, non-linear dynamic response of structural foundation, liquefaction of loose ground under vibrational excitations, and rupture of earthquake fault. Results are presented from several numerical experiments done on dense sphere assemblies in three dimensions. The experiments are intended for comparison with physical experiments, described by Ishibashi and Chen (ref. 1) and the theoretical results of Jenkins (ref. 2). Periodic boundaries are used to eliminate boundary effects; the effect of sample size is studied in one series of tests, using linear contact stiffnesses. In another test series, contact stiffnesses are nonlinear, according to the Hertz theory. In general, numerical and physical results agree, except for the volume strain observed in a triaxial extension test: this discrepancy may indicate the presence of an initial fabric in the physical sample.Results achieved using the model idealized as a continuous medium, which have been widely applied in the past, differ from those gained by using the granular assembly model adopted in this study. Ignoring the influence of movements of soil particles, including subsidence and rotation of particles, in the former method seems to be the cause of such differences. © 1988 Elsevier B.V.