Analytical method for laterally loaded piles in soft clay considering the influence of soil outside the scour hole on the effective overburden pressure

Scour reduces the effective overburden pressure and the undrained shear strength of soil, thus affecting the lateral load-bearing capacity of pile foundations. Compared with general scour, local scour can decrease the reduction of the effective overburden pressure and the undrained shear strength around the pile due to the existence of soil outside the scour hole. To fully reflect the actual situation at a site, the behavior of laterally loaded piles in soft clay should consider both the scour-hole dimensions and the soil stress history. This paper proposes a closed-form analytical solution for laterally loaded piles in soft clay that can simultaneously account for the changes in effective overburden pressure and undrained shear strength caused by the scour-hole dimensions and the soil stress history based on the p–y curve proposed by Matlock. The average reduced stress is introduced according to Boussinesq’s point load solution. Case studies demonstrate that the analytical method is reliable with reasonable accuracy. According to the parameter study, the load eccentricity is the most sensitive factor compared with the changes in soil properties caused by the scour-hole dimensions and the soil stress history.