Behaviour of combined pile-raft foundation (CPRF) Under static and pseudo-static conditions using PLAXIS3D

Abstract

In this study, effect of pile head connection condition on the behavior of Combined Pile-Raft Foundation (CPRF) by using finite element based geotechnical program PLAXIS3D is investigated. The finite element model is first validated with experimental results from available literature. Thereafter, the responses of CPRF in terms of settlements, normalized bending moments (M/M_max) and normalized lateral displacements (u/D) under available input earthquake loadings, like 2001 Bhuj, 1989 Loma Prieta and 1995 Kobe are studied. Results show that connection condition has little influence on settlement under vertical load alone whereas load sharing by raft varies from 30% for hinged connection to 54% for rigidly connected CPRF model. Under the application of lateral load including various earthquake loads, raft mobilizes ultimate resistance at faster rate compared to pile irrespective of connection rigidity. Connection rigidity played an important role in bending moment variations, lateral displacements and rotations.