Use of centrifuge experiments and discrete element analysis to model the reverse fault slip

This study presents a series of physical model tests and numerical simulations using PFC 2D (both with a dip slip angle=60° and a soil bed thickness of 0.2 m in model scale)at the acceleration conditions of 1g, 40g, and 80 g to model reverse faulting. The soil deposits in prototype scale have thicknesses of 0.2 m, 8 m, and 16 m, respectively. This study also investigates the evolution of a surface deformation profile and the propagation of subsurface rupture traces through overlying sand. This study proposes a methodology for calibrating the micromechanical material parameters used in the numerical simulation based on the measured surface settlements of the tested sand bed in the self-weight consolidation stage. The test results show that steeper surface slope on the surface deformation profile, a wider shear band on the major faulting-induced distortion zone, and more faulting appeared in the shallower depths in the 1-g reverse faulting model test than in the tests involving higher-g levels. The surface deformation profile measured from the higher-g physical modeling and that calculated from numerical modeling show good agreement. The width of the shear band obtained from the numerical simulation was slightly wider than that from the physical modeling at the same g-levels and the position of the shear band moved an offset of 15 mm in model scale to the footwall compared with the results of physical modeling.