Dynamic behaviour of a piled raft resting on saturated Kasai River sand

Abstract

ABSTRACT The present work intends to calibrate the cyclic triaxial test and validate the 1-g shake table test of piled raft on saturated Kasai River sand. The outcome of the cyclic tests on Kasai river sand is already reported in the literature, but the present paper attempts to identify and explain the failure modes of the cyclic triaxial test as well as to numerically calibrate the experimental data(s) for relative density of 40% and 60%. For numerical validation and calibration, a bounding surface plasticity model is used. The calibrated parameters obtained from the element tests are used for validation of 1-g shake table test of piled raft resting on saturated sand. The numerical predictions are in good agreement with the experimental observations (in terms of acceleration, pore pressure). In addition, the effect of superstructure loading on piled raft is investigated in terms of variation of pore pressure (or effective stress) near and away from the structure and mechanism for vertical settlement of piled raft is identified. The relevant parameters related to seismic design of piled raft are identified and design guidelines in terms of strength and serviceability has been proposed.