Effects of Soil Slope on Lateral Responses of Piled Raft Foundations in Cohesive Soil

The lateral capacity of piles decreases as they are installed closer to slopes. In cases where lateral load governs the design, larger foundations are necessary to ensure the serviceability of the foundations. The concept of piled raft foundations has been introduced to enhance the lateral capacity of pile foundations by integrating the capacity of the raft's base and piles. This makes piled raft foundations a cost-effective alternative to pile group foundations. The present study aims to investigate the impact of soil slopes on the lateral responses of piled raft foundations to evaluate the ability of piled raft foundations installed near slopes to resist lateral loading. Three-dimensional finite element analyses were conducted using PLAXIS 3D, focusing on the case study of the piled raft foundations having 3x3 piles. The findings revealed that the lateral capacity of piled raft foundations decreased when they were installed at distances closer than 8D to a slope. Meanwhile, the slope had an insignificant effect on the lateral load-sharing ratio of the raft. Therefore, piled raft foundations have the potential to increase the overall capacity of the foundations and minimize the lateral load transferred to pile components.