Finite Element Modelling of Piled Raft in Sand Under Earthquake Load

Abstract

AbstractIn this paper, finite element (FE) simulations are carried out in PLAXIS to investigate the seismic response of piled raft embedded in sand using pseudo-static approach. A three-dimensional FE model of piled raft, verified with published data in literature, is utilized to study the response of piled raft for Uttarkashi (1991) and Sikkim (2011) earthquake pseudo-static loading conditions. This pseudo-static load is applied at the level of the raft in addition to the vertical load. Based on the numerical results, the piles are found to carry about 60–75% of the applied pseudo-static load. This pile load proportion increases with increasing magnitude of pseudo-static load for different earthquake events. Lateral displacement and bending moment are observed to attain their maximum values at the pile head. The bending moment of the pile is found to change from positive to negative along the length of the pile and finally becomes zero at the pile tip.KeywordsPiled raft systemPseudo-static approachEarthquake loadFinite element modelling