3D Numerical Analysis of Single Pile and Pile–Raft Subjected to Vertical Loading

Adopting pile–raft foundations for large structures is advantageous over conventional pile foundations owing to their reduced differential settlements. The structural behaviour of this pile–raft foundation system depends on its load-sharing ratio. Further, the soil–pile–raft interface conditions may influence the structural performance of a pile–raft foundation system. Hence, a 3-dimensional numerical analysis was carried out to study the impact of different parameters on the pile–raft foundations subjected to vertical loading. Sensitive analysis was done by varying the parameters such as soil characteristics (cohesion and friction angle), pile diameter, pile spacing, pile group arrangement and raft thickness. The results indicate that the settlement behaviour and load-carrying capacity of the single pile system have been considerably impacted by the change in the frictional angle of the soil strata and the corresponding settlement decreased with an increase in the frictional angle of the soil. Further, the load–settlement behaviour of the piled raft system is greatly influenced by the parameters such as pile diameter, pile length, raft thickness and pile group arrangement. In addition, it has been observed that the pile group arrangement plays an important role in the load-carrying capacity of the system.