Numerical analysis of mechanical factors influencing the bearing capacity of piled raft foundation on saturated overconsolidated clay

Abstract

Piled raft foundation is used to reduce the settlement of soft clay by using the friction between the pile and soil. Recently, a numerical approach (FEM) was adopted in a study to clarify the mechanism of the bearing capacity of piled raft foundation. In addition, the finite deformation theory and the subloading model based on the unconventional plasticity theory are introduced. Under a small load, the distinct difference between the infinitesimal and finite deformation analyses cannot be observed, but when the deformation is large, the difference is remarkable. This is because the influence of geometric nonlinearity becomes large. The behavior of over-consolidated soil can be expressed appropriately using the subloading model. When the load is applied at the piled raft foundation, compression and shear behavior are observed around the element at the tip of the pile. Finally, the possibility of deformation prediction using FEM is demonstrated.