Probabilistic analysis of multi-layered soil effects on shallow foundation settlement

Abstract

The results of a preliminary investigation into the effects of multi-layered soil on foundation settlement are reported in this paper. In this study, the settlement of a square pad footing placed on two-layered soil profile is examined. Using a combination of Finite Element Method (FEM) analyses and random fields simulation, probabilistic analyses of the settlement of footing founded on two-layered soil profile is established through Monte Carlo simulation. The Young’s modulus field has been simulated via Local Average Subdivision method (LAS) with a fixed mean, various coefficients of variation and spatial correlation structures. The coefficients of variation and spatial correlation structures in each layer are set to be different. It is assumed that the boundary between two soil layers is abrupt as may be represented by faults and geological unconformities in the soil mass. The results of the analyses indicate a modest decrease in the coefficient of variation of settlement of the 2-layered soil profile compared to the settlement of the uniform single layer soil mass.