Modeling the p-delta behavior of single friction pile in compacted fine-grained soils

In this paper, the contribution of the matric suction towards the shaft bearing capacity of a single pile loaded in a compacted fine-grained soil (i.e. Indian Head till) is investigated based on the load-displacement (i.e. p-delta) relationships derived from both model pile tests and Finite Element Analyses (FEA). The FEA are undertaken using the commercial software SIGMA/W. A modulus of elasticity model and a modified Mohr-Coulomb yield surface function that consider the contribution of the matric suction are jointly used in the FEA to formulate an elastic-perfectly plastic constitutive model. There is a reasonable agreement between the p-d relationships modeled from the FEA and measured from model pile tests. Both measured and modeled results suggest that there is a significant contribution of the matric suction towards the shaft bearing capacity of single piles in compacted fine-grained soils.