Simplified method of estimating the dynamic impedance of a piled raft foundation subjected to inertial loading due to an earthquake

摘要

Simplified method of estimating the dynamic impedance of a piled raft foundation subjected to the seismic forces of building is presented. Parametric analysis was first performed to calculate the impedance of piled raft, spread, and pile foundations in the frequency domain. Base on calculated impedances, arbitrary functions were newly derived to describe the dynamic interaction factor between the raft and the pile group that constitute the piled raft foundation. It is possible to easily evaluate the impedance of piled raft foundations using the equation for the dynamic interaction factor along with the impedances of the corresponding spread and pile foundations.