Computation of degradation factors of p-y curves in liquefiable soils for analysis of piles using three-dimensional finite-element model

This paper presents a procedure to compute the values of degradation factors of p-y curves in the pseudo-static analysis of piles in liquefiable soils. Three-dimensional finite-element model was used for the computation of p and y values using OpenSees computer package. The piles were modeled using beam-column elements and elastic section. The soil continuum was modeled using brick elements and a two-surface plasticity model. By comparing the results of models in two cases of liquefiable and non-liquefiable, values of degradation factors were obtained. Validation of the degradation factors computed was conducted through the centrifuge test results. The simulation results showed a similar trend between degradation factor variation in different densities and sands. With increasing depth, the degradation factor increased. By comparing the results of pseudo-static analysis with the centrifuge test results, it was concluded that the use of the p-y curves with computed degradation factors in liquefiable sand gave reasonable results.