Mitigation of Liquefaction-Induced Foundation Settlements Using Sheet Piling and Lowering Groundwater Level

This paper evaluates three ground improvement techniques used in engineering practice: (1) press-in sheet piles around the foundation, (2) lowering groundwater level (GWL) by 1.5 cm, and (3) a combined approach. The objective is to investigate their effect on excess pore water pressure (PWP), foundation settlement, and tilting, and propose technically sound and economically viable measures. In this study, a series of moderate scale 1-g shake table experiments were conducted at the University of Nevada, Reno, to evaluate the performance of those techniques in liquefiable soils. A 1/5 scaled model consisting of three soil layers with varying densities, namely the crust, liquefiable, and dense layers, was prepared, and a shallow foundation was placed over the crust layer. The proposed ground improvement techniques were then applied to the model ground, which was excited using a shaking duration of 13 s and a PGA of 0.28g. Experiments showed that all the mitigation measures reduced the foundation settlement and tilting and generated excess PWP. Among the three ground improvement techniques, the combined technique proved most effective, reducing excess PWP by 74%, and foundation settlement and tilting by 87% and 95%, respectively. These findings offer valuable insights for engineering practice in mitigating liquefaction-induced foundation settlements.