Comparison of 1D and 2D liquefaction assessment methods considering soil spatial variability

Abstract

1D soil column techniques are widely used to evaluate the potential of liquefaction in a system of soil layers. This approach generally leads to large inaccuracies since (1) soil layers are hardly homogeneous and perfectly horizontal and (2) horizontal effects are neglected. To demonstrate the limitation of 1D strategies and the need for 2D simulations, a series of benchmark problems are proposed and studied considering a fully coupled RFEM framework with small strain effects to account for cyclic behavior. First, a 1D simulation of a homogeneous material is tested against similar 1D problems including the spatial variation of soil properties (in this case void ratio). Then, a 2D domain is analyzed using the void ratio distribution obtained from combining the 1D columns. This investigation demonstrates that, by combining the effects of the horizontal direction and the spatial distribution of the soil properties, liquefaction triggering, spatial spreading and propagation extent may change significantly.