Performance of unequal piled raft under vertical loading in cohesionless medium

The performance of piled rafts with unequal pile lengths in cohesionless soil under vertical loading was investigated in the present study through experimental and numerical analysis. A pattern function is used to define the pile length arrangement. The motivation for considering such a function is to ensure that the varying pile lengths follow a suitable geometric pattern, and it does not obstruct the construction practice in field applications. The piles at different locations within the raft were equipped with strain gauges to observe the strain distribution along their lengths during the static load test. Load sharing was evaluated by placing an earth pressure cell beneath the raft. A three-dimensional finite element analysis was used to simulate the experimental results aimed at assessing the load settlement and load-sharing responses. A comparison was conducted to verify the reliability of the tests. Subsequently, a detailed parametric study was conducted in accordance with different pattern functions, pile spacing, and pile locations in the piled rafts. The load settlement, load sharing, and bending moment of the raft were evaluated. An understanding of the pile behavior at different locations within the group will be helpful in selecting the suitable pile geometry during actual construction in the field. A foundation designed by considering the optimized pile length will be helpful in developing a more economical and resilient foundation system.