Laterally loaded pile in unsaturated soils, a numerical study

The influence of partial saturation on laterally loaded piles response has been studied perform-ing three-dimensional simulation using a finite element code. The analysis simulated a single vertical floating pile embedded in a normally consolidated silty clay, subjected to a static horizontal force applied at pile head. The study aims at exploring the influence of the relative position of water table with respect to the pile length. The hydro-mechanical propriety of soil is kept constant. The constitutive model adopted to simulate the soil stress-strain response is an extension of modified Cam-Clay model that considers the evolution of the yielding surface due to variation of saturation degree. The model is formulated in terms of modified Bishop effective stress, which allows switching continuously from saturated conditions to unsaturated conditions and vice ver-sa. The modified formulation of the hardening parameter allows to correctly reproduce the volumetric behaviour observed in wetting and drying path.