Single Piles in Liquefiable Ground

This thesis focuses on seismic response of piles in liquefiable ground. A three-dimensional unified plasticity model for large post-liquefaction shear deformation of sand was formulated and implemented for parallel computing, based on which a three dimensional dynamic finite element analysis method for piles in liquefiable ground was developed. Through a combination of case analysis, centrifuge shaking table experiments and numerical simulations using the proposed methods, the seismic response patterns of single piles in liquefiable ground were revealed, including: basic force-resistance mode, kinematic and inertial interaction coupling mechanism and major influence factors. A beam on nonlinear Winkler foundation (BNWF) solution and a modified neutral plane solution were developed and validated against centrifuge experiments for piles in consolidating and reconsolidating ground. The axial pile force and settlement during post-earthquake reconsolidation was studied, showing pile axial force to be irrelevant of the reconsolidation process while settlement to be process dependent.