Responses of Piled Raft Foundations in Layered Soils Subjected to Eccentric Vertical Loading

The concept of raft foundations enhanced with piles (typically named piled-raft) has received considerable attention in recent years. Raft foundations are widely used in supporting structures when relatively strong layers are present at shallow depth. Sometimes, although the shallow layers of soils have adequate bearing capacity, a raft foundation can induce excessive settlements. In such cases, piled rafts (raft foundations enhanced with piles) are used. The behaviour of piled raft changes significantly in layered soil. It had been seen for piled raft installed in layered soil the reduction in settlement was more pronounced with smaller length of piles, compared to homogenous soil. In this study a parametric investigation were conducted (studying the effects of variation in ratio of load eccentricity to width of footing, ratio of pile length to diameter, pile numbers and arrangement of the piles on the responses of the foundation) to observe the behaviour of piled rafts in layered soils with eccentric loading. Rafts with connected piles and rafts reinforced with unconnected piles were considered.