Simplified non-linear approaches for response of a single pile and pile groups considering progressive deformation of pile-soil system

This work presents a simplified approach for the nonlinear analysis of the load-displacement response of a single pile and pile groups embedded in multilayered soils. A hyperbolic model is used to capture the relationship between the skin friction and the pile-soil relative displacement developing along the pile-soil interface. The shaft displacement is assumed to be composed of the pile-soil relative displacement developing at the disturbed soil around the pile shaft and the elastic vertical soil displacement developing in the soil mass. The relationship between the shaft displacement and the skin friction is then presented. Moreover, a hyperbolic model is also used to capture the relationship between end resistance and pile end displacement. Considering the interactive effect among piles, hyperbolic models of an individual pile in pile groups are proposed. As to the analysis of the response of a single pile and pile groups, considering the progressive deformation of the pile-soil system, a highly effective iterative computer program is developed using the proposed hyperbolic models. Comparisons of the load-settlement responses demonstrate that the proposed method is generally in good agreement with the field-observed behavior and the calculated results derived from other approaches.