Lateral loading of a pile using strain wedge model and its application under scouring

The scour hole around a pile will reduce the capacity of a laterally loaded pile. The strain wedge model is capable to derive a p–y curve for the analysis of a lateral loaded pile on a nonlinear Winkler foundation. To improve and extend the ability of the strain wedge method, a modified strain wedge (MSW) method is developed, in which a nonlinear lateral deflection of the pile is assumed to describe the varied soil strain distribution in the passive wedge. And then by treating the soil weight involved in the strain wedge as a vertical load at the bottom of the scour hole, an equivalent wedge depth is obtained to consider the effect of scour hole dimensions on the response of laterally loaded piles in sand. The validity of the MSW model is proved by comparisons with a centrifuge test without scour. And its applicability in the problem of a pile with scour is performed by a comparison with a model test and a FE analysis. The analysis shows the pile displacement at the pile head with scour can be obtained by multiplying the corresponding deflection without scour with an amplification factor related to scour depth at large load level.