Abstract
This paper which concerns the dynamic analysis of ground pile foundations places interest not only on evaluating the pile head impedance function and the effective pile head input motion but also on investigating the pile behavior during soil-structure interaction. The thin layer formulation is applied for soil analysis. The transfer matrix procedure is used for pile analysis. The flexibility approach that takes the interaction force as unknown is adopted for establishing the coupled behavior under the perfect bond condition. For group piles, the rigorous 3-dimensional analysis and the ring pile approximation are made for comparison. Soil reaction and internal forces of pile are investigated and the contributions from the inertia interaction and the kinematic interaction are clarified. The validity of the Chang's formula is checked from the design point of view of piles.
