Effect of Soil Slope on Lateral Response of Piled Raft Foundations in Cohesive Soil

The advantages of the piled raft foundations system over conventional pile group foundations have been demonstrated in previous studies. In a pile raft foundation, the raft load capacity is extensively investigated in level ground conditions; its behaviour in a soil slope is limited. In the present study, three-dimensional finite element analyses using PLAXIS 3D software were performed to examine the effect of the soil slope on the lateral response of the piled raft foundation. The study showed that the lateral capacity of piled raft foundations decreases when installed within a certain distance (less than 8 times the pile diameter) from a slope. Furthermore, the enormous effect of slope occurs at distances nearer than 4D. Despite a decrease in lateral capacity when installed near slopes, the effect on the piles is insignificant, especially the rear piles. As a result, the distance between the piled raft foundations and the slope is a key factor that needs to be considered to improve design guidance to reduce construction costs.