Stochastic Analysis for Bearing Capacity Determination of Shallow Foundations on Thin-Tilted Anisotropic Soils

The soil stratum is heterogeneous and may be tilted with significant influence on the footing bearing capacity (BC). In this paper, a combination of influence of the anisotropy orientation and thickness of soil layer and rock stratum inclination on the BC of strip footings was evaluated using a random finite-difference method (RFDM). The Monte Carlo simulation (MCS) approach was used to elucidate the effect of spatial variability, and soil strength characteristics were assumed as log-normal and bounded random fields. The failure mechanism and produced shear strain in probabilistic method were compared to those obtained from deterministic analysis. The results showed that the soil stratum inclination has a significant effect on the footing BC magnitude, which reaches a minimum value when the deposition orientation is 45 degrees-phi/2 with the horizontal direction (phi = soil friction angle). Parametric studies were performed on the variability level of strength parameters, the correlation coefficient of strength characteristics, correlation length, soil layer thickness, and stratification orientation.