Reliability Study of Bearing Capacity of Foundations under Dynamic Loadings

Abstract

The main objective of this thesis is to investigate the impact of uncertainties on the bearing capacity of shallow foundations under seismic loading by employing probabilistic approaches. At the first stage, the Karhunen-Loève (KL) expansion method within the context of random field theory was utilized to explore the influence of soil and earthquake parameter randomness on the seismic bearing capacity. The seismic bearing capacity equations established by Conti (2018) were applied in the analysis for two soil types supporting shallow strip footings: purely cohesive soil and cohesive-frictional soil. The results indicated that, in the context of statistical and probabilistic results, prioritizing the coefficient of variation is essential for accurately capturing the variability and making reliable inferences. At the second stage, a formulation for determining the seismic bearing capacity factor of a shallow strip footing influenced by torsional surface wave propagation and resting on anisotropic non-homogeneous soil was presented. The limit equilibrium method in conjunction with the pseudo-dynamic approach are used. In addition to that, a reliability analysis based on Monte Carlo simulation was conducted in order to incorporate the soil-earthquake uncertainties and investigating their effects. It was found that the proposed seismic bearing capacity factor can be applicable in order to quantify the torsional wave propagation, the anisotropy and the non-homogeneity of the soil properties.