Numerical analysis for deformational behaviour of different length piled raft in cohesive soils

Abstract

The deformation behavior of pile groups in cohesive soils subjected to uniform distributed load reflects the interaction between pile groups and surrounding soils especially differential settlement. To evaluate the performance of pile groups numerical analyses are modeled using finite element code. In this paper a methodology for the design of floating pile raft foundation achieving the safety and economic condition for this type of geotechnical structure is presented. This methodology is used in the analysis of a case study of a reinforcement concrete raft supporting 2500 ton oil storage tank on a very soft alluvium clay deposit and resting on 137 piles. The results of the finite element analysis are compared with the full scale measurements carried out in the site. The optimization of the pile's length distribution is evaluated for this case to meet four conditions of average settlement, differential settlement, shear and moments in addition to the probability of failure for this type of structures.