An alternative p-y method for piles in cohesive soils under monotonic lateral loading

Abstract

Piles as onshore and offshore foundation structures are often horizontally loaded. The usual calculation method for the behaviour of piles under such loads is the p-y method. For piles in cohesive soil, several p-y methods are proposed in literature, leading in general to differing results. A finite element model dealing with the behaviour of horizontally loaded piles in clay soils was established and validated against field tests. Utilising the results of a vast number of numerical simulations, a new p-y method was developed, which gives reasonable results over the entire range of possible loads for piles of almost arbitrary diameters and embedded lengths in clay soils of varying consistency. The method requires in total six soil parameters and accounts for the actual deflection of the pile and also the effect of pile tip shear resistance by iteratively adapted y-multipliers which depend on the course of the deflection line and the distance of the considered point to the pile tip. The new method can be generally used for calculation of the bearing behaviour of piles in soft clay under monotonic loading and can serve as a reference for consideration of cyclic load effects or softening effects in stiff clays.