Side resistance of drilled shafts in granular soils investigated by DEM

The paper presents a numerical study on the side resistance of a drilled shaft in granular materials. The numerical result is used to develop new design equations for the side resistance of drilled shafts in granular soils. The Discrete Element Method (DEM) is used to model a drilled shaft in granular material. The granular material is represented as assemblies of ellipsoidal particles. Nominal side resistance is represented as the product of a parameter (beta) and vertical stress. The numerical result shows that the relationship between beta and void ratio can be described by a hyperbolic function for a given vertical stress. DEM result is also compared with three design equations. Although these design equations capture the decrease of beta with depth, deviation is observed between the DEM results and the design equations. Finally, new design equations based on state parameter are proposed. (C) 2015 Elsevier Ltd. All rights reserved.