A Numerical Study on the Estimation of Liquefaction-Induced Free-Field Settlements by Using PM4Sand Model

The present paper treats the estimation of liquefaction-induced, free-field settlements using two-dimensional, fully coupled, finite element (FE) analyses. The PM4Sand model is used to simulate the liquefaction behavior of a homogeneous sand layer with three different relative densities of 35%, 55%, 75% under eleven different strong ground motions. The results of FE analyses are compared with those obtained from the well-known, semi-empirical methods in the literature. The numerical analyses show that, in case of a relative density of 35%, in general, the majority of earthquake-induced settlements occur in the period, in which the excess pore water pressure resulting from the strong ground motion begins to dissipate. The liquefaction-induced settlements are influenced by not only the moment magnitude and peak ground acceleration, but also other parameters of the ground motion. Furthermore, it has been shown that the evaluation of the liquefaction potential using finite element and semi-empirical methods gives similar results. However, the semi-empirical methods yield mostly larger settlements than those obtained from the FE analyses.