Experiment and numerical simulation of pile stress on pile and piled raft foundations subjected to ground deformation during earthquakes

There has been much experimental and analytical research on pile and piled raft foundations investigating settlement behavior and the load-sharing ratio between the raft and piles for vertical loadings, but insufficient study on the lateral resistance of these foundations to seismic loads, particularly ground deformations. In order to evaluate the stresses on pile and piled raft foundations subjected to ground deformation, we performed centrifuge model tests and numerical analysis. For piles, the interaction between the piles and the soil is different than with only vertical loading and the bending moment at the top of the piles was large. On the other hand, for piled rafts, since the behavior of the pile and free field soil are almost the same, the bending moment at the top of the piles is smaller. The results indicate that the simulation represented the pile and piled raft foundations correctly.