A NUMERICAL STUDY ON SOIL-GROUP-PILE-BRIDGE-PIER INTERACTION UNDER THE EFFECT OF EARTHQUAKE LOADING

摘要

There have been many costly damages of group-pile foundation of bridge-pier in soft or saturated-medium dense sandy ground after strong earthquakes. This study investigated the dynamic behavior of a 2 x 2 bridge-pier-group-pile foundation installed in a two-layer ground commonly found in Japan. A series of three-dimensional (3D) effective stress analysis, which adopted advanced cyclic elasto-plastic soil model and nonlinear axial force dependence reinforced-concrete model, has been implemented to demonstrate the interaction between the soil-group-pile-bridge-pier during an earthquake of the magnitude of the 1995 Kobe earthquake. The damages of the 2×2 group-pile foundation have been quantitatively found to be either caused by the inertial loading of the superstructure or the kinematic interaction of the soils.