Seismic Behavior of Piled Raft under Moderate and Strong Earthquakes Based on Observation and Numerical Simulation

摘要

The seismic behavior of a piled raft foundation with cement deep mixing walls (DMWs) in soft ground was investigated based on the observation results of the 2011 Tohoku Earthquake. The results were examined focusing the effects of inertial force from the structure and action of ground movements on the foundation system. Furthermore, the seismic performance under strong earthquakes was also discussed using the previous 3D finite element (FE) analysis results. Consequently, it was found in soft ground that the bending moment near the pile head were affected mainly by the lateral ground deformation, rather than the shear force resulted from the structure inertial force. It was also found that the DMWs restrained the amplification of ground deformation in the grids and this would lead to the significant decrease in bending moment near the pile head.