Experimental validation of a numerical model for the interaction of dip-slip normal fault ruptures, sand deposits, and raft foundations

Abstract

An incomplete understanding of the failure mechanisms in fault rupture propagation has led to inconsistent and insufficient regulations in building codes. In the present study, a sophisticated numerical model is calibrated and validated in order to clarify a complex problem involving the interaction of fault ruptures, medium dense Fontainebleau sand deposits, and existing structures across the fault plane. Calibration is performed using direct shear test data. Repeatable centrifuge models of dip-slip normal faults with a dip angle of 60° in the free field condition and light and heavy rigid strong raft foundations are used for the validation. The present numerical model satisfactorily simulates the centrifuge models. Rigid rafts divert the shear bands so as to bypass the rafts, rather than rip them apart. The rafts tilt on the foundation soil during fault rupture. The raft-tilting increases as the raft bearing pressure on the soil decreases.