Seismic behavior and reinforcement mechanisms of earth dam and liquefiable foundation system by shaking table tests and numerical simulation

Abstract

Earth-rockfill dams suffer from various geotechnical disasters during seismic hazards, and liquefiable foundation will aggravate these damages by reducing the foundation bearing capacity. In this research, a quasi-three-dimensional earth dam and liquefiable foundation model was designed to study the seismic behavior, liquefaction process and reinforcement mechanism. Three typical models, including unreinforced (UR), raft reinforced (RR), and gravel pile reinforced (GPR) models, have been investigated by 1-G shaking table test and numerical simulation. The experiment of model UR was utilized for calibrating the numerical parameters via the inverted method, and two other experiments were set as the simulation targets using the above-mentioned parameters. The experiment and simulation results have shown that uneven settlement and cracks appeared in model UR are mainly caused by foundation liquefaction rather than seismic residual deformation. The raft slab and gravel piles mitigate the uneven settlement and cracking potential significantly by multiple reinforcement mechanisms including the supporting effect, drainage effect, and stiffness improvement effect.