Using peak ground velocity to characterize the response of soil-pile system in liquefying ground

Performance of a soil-pile system can be significantly influenced by many characteristics of an earthquake ground motion, and it is vitally important to identify the ground motion parameters that have the most significant effects on the response when predicting the level of movement or damage in the pile. In this paper, three-dimensional finite element (FE) analysis was conducted to simulate a centrifuge experiment on the nonlinear behavior of a pile founded in liquefiable soil subjected to strong earthquake motions. The result of the FE analysis was found to be in reasonable agreement with the experimental data. As such, the calibrated FE model was used to investigate the influence of ground motion parameters on the pile-soil response in both liquefied and non-liquefied soils. It was found that peak ground velocity (PGV) is an appropriate ground motion parameter to characterize the response of the soil-pile system in liquefying ground. The maximum pile bending moment, pile lateral displacement, and soil lateral displacement increased with increasing PGV. Moreover, near-fault ground motions could result in more severe damage to the pile compared to far-fault grounds motions. This study provided a new insight on the influence of ground motion parameters, in particular PGV, on the dynamic performance of a pile foundation.