Modeling and safety assessment of a piled raft comprising defective piles

This paper deals with the modeling of a piled raft system comprising a number of defective piles using a nonlinear finite element analysis. A series of single-pile compression tests, involving both normal and defective piles, is investigated. The results of these analyses permit the determination of the probable causes of imperfection for the defective piles which help in determining the numerical parameters that are employed for the three-dimensional analyses of the problem in hand. Beside the piled raft system, the study extends to analyze both the traditional raft and the conventional pile group systems in order to compare the behaviors and safety margins of the three systems. In addition, a problem of a piled raft considering ideal pile behavior is investigated. the results show that the percentages of load directly transferred by the raft are considerable but have different values in different systems depending on the number of the defective piles.