Seismic Performances of Pile Groups in Inclined Soil Layers Subjected to Strong Motions

In order to insure the safety of pile groups on the inclined soils in the earthquake prone area, analysis of seismic performances of pile groups in the inclined soil layers is of prime importance. Centrifuge tests of 50g and responding numerical simulations are conducted to investigate the seismic performances of pile foundation under strong ground shaking conditions. Moreover, detailed discussions and comparisons between numerical modeling and centrifuge tests are included. These centrifuge test model consisted of a model pile foundation of 2 x 2, 10 times diameter spacing on an inclined dry or saturated layer of slope angle = arctg(l/2). Effective stress analysis method based on a multiple shear mechanism is employed for conducting the numerical predictions and validation. It is concluded that the measured and computed responses of acceleration, displacement are in good agreement. The physical and numerical models both indicate that the lateral displacements of pile groups are much larger in laterally spreading soils than in dry soils. The dynamic centrifuge test and the numerical simulation method proposed in this paper is reliable and applicable for analyzing seismic performance of soil-pile system in inclined soils subjected to strong motions.