Bearing Capacity Assessment of a Shallow Foundation on a Two-Layered Soil Using the Random Finite Element Method

In this paper results of stochastic analysis of bearing capacity of a shallow foundation on a two-layered soil are presented. Computations use the random finite element method (RFEM) which allows soil strength parameters to be modeled as random fields. In this study, both the friction angle and the cohesion were characterized by two dimensional random fields using bounded and lognormal distributions respectively. Other soil properties such as Young’s modulus, Poisson’s ratio and soil unit weight were assumed to be deterministic, as their influence on bearing capacity can be neglected. Results are presented for the cases of “weak” over “strong”; and “strong” over “weak” while simultaneously considering various thicknesses of the layers, anisotropic correlation lengths and the coefficients of variation of the friction angle and cohesion. Conclusions indicate the cases in which stochastic characterization of soil parameters can significantly affect the stochastic bearing capacity of shallow foundations.