Analysis and design of piled raft foundations in cohesive soils

In this study, the effects of the pile group on the load-sharing ratio between the raft and the piles in piled-raft foundation applications constructed in cohesive soils were investigated with the aid of analytical methods and numerical analysis. The parameters that affect the piled-raft foundations due to different layouts of piles used in and obtained by numerical analyzes were compared with the results calculated by analytical methods. The aims of this thesis are to develop a numerical model for piled-raft foundations which is based on finite element method, to investigate the changes occur in load-sharing ratios depending on the number of piles and to compare the results obtained with analytical methods to the results obtained from numerical analyzes. Another significant aim of this study is to show that the commonly used approach of ignoring the effects of the raft to the load-sharing ratio of piled-raft foundation in conventional foundation design is not applicable and to prove that the raft has significant effects on the load-sharing ratio in piled-raft foundations. In addition, the study aims to investigate the effects of some of the important mechanical parameters of cohesive soils as well as the effects of some of the design and mechanical parameters related to pile and raft dimensions, on load-settlement relationship and load sharing ratio of piled raft foundations.