Micro-mechanical analysis of caisson foundation in sand using DEM : particle breakage effect

Abstract

Particle breakage plays an important role in strength degradation of granular soils and thus needs to be considered in the analysis of caisson foundation. However, no relevant research has been reported before. In this study, the effect of particle breakage on the behavior of caisson foundation is investigated with discrete element method (DEM). Firstly, breakage models are reviewed and the one based on replacement method is adopted. Biaxial tests are conducted to validate the breakage model. Then a caisson foundation is investigated with the consideration of particle breakage. This study demonstrates that: (1) both the horizontal and rotational bearing capacities are decreased by particle breakage; (2) successive breakages tend to happen near the caisson skirt, while individual breakages are more common in regions far from the skirt; (3) the particle rotation, APR and force chain concentration are much smaller when particle breakage is considered; (4) particle breakage decreases the magnitude of the anisotropy induced by external loads.