AXIAL LOAD-TRANSFER FOR PILES IN SAND .2. NUMERICAL-ANALYSIS

A nonlinear finite element analysis was carried out to model the pile tests presented in the companion paper which included a new procedure to calculate the residual load in the test pile. The soil at the site consists of sand, and this second paper applies a bounding surface plasticity model in a finite element analysis to describe the behavior of the sand subjected to repeated loading. A close agreement was achieved between the calculated and measured values for the applied load versus pile head movement, load transfer, and shaft resistance in compression and tension testing. In addition, the analysis demonstrated a reduction in shaft resistance and a buildup of toe resistance with repeated loading. The finite element calculations as well as the measurements indicate that the critical-depth concept is incorrect.