AbstractIt is believed that a dynamic analysis is urgently required to provide a more reliable numerical method for seismic evaluation of a full system, which includes foundation, super structure, and ground in earthquake zones such as Taiwan and Japan. A centrifugal model test of pile foundation is simulated numerically using a three-dimensional finite-element model (3D-FEM) code in this study. In the numerical simulation, parameters of the sandy soils in tij model that are derived from accumulated experiences in static tests are first calibrated by centrifugal vibration tests of sandy ground. Model tests of a single pile foundation installed in grounds of same unit weight of soil as in the static tests are then simulated using the calibrated parameters. The numerical simulation resulted in a good agreement with the corresponding physical model tests. By comparing the computed and the observed results, one can find and confirm that it is necessary to employ an appropriate soil model to reproduce dynamic soil behavior due to major vibration. Representation of pile by beam element in the numerical analysis is applicable when attention is paid on the response acceleration of top of pile foundation, on soils at some distances to the pile foundation, and on bending moment of the pile in a stiffer ground. Equal-displacement boundary condition for two-side boundaries is proven to be efficient. To reduce the computation time, the assumption of a constant damping of viscous matrix is acceptable.
Model tests and theoretical analysis of the vertical vibration of a single pile in saturated sandy soil