Evaluating liquefaction induced settlement of shallow foundation on layered soil deposit

Abstract

The occurrence of liquefaction in saturated layered soil deposit underlying the shallow foundation can cause a wide range of problems from settlement to tilting of structures and foundations. It this study in order to evaluate the liquefaction induced settlement of shallow foundation on the ground surface of layered soil deposit, numerical studies have accomplished. The soil deposit involves a continuous saturated fine sand that is sandwiched between two dense continuous sand layers and the whole system had been subjected to a base shaking. The settlement of shallow foundation has been evaluated by considering the influence of relative density (Dr) of middle sand layer. The variation of relative density of middle continuous soil layer was examined by using the finite element method in OpenSEES software. It was observed that the liquefaction has occurred up to the depth of 6 m. In addition, by examining the slope of the settlement–relative density curve, it was found that in continuous fine sand layer for relative densities higher than 60% the effect of this layer on settlement of shallow foundation can be neglected, but for relative densities less than 60% the slope of curve is sharper and as a result, the shallow foundation is experienced higher settlement with 17 cm for Dr = 40% in compare with settlement 10 cm for a uniform soil deposit with Dr = 75%.