Abstract
This study presents 3D Discrete Element Method (DEM) simulations to analyse earth pressure distributions under active rigid wall movements in both loose and dense sand. A comprehensive simulation procedure is provided, with parameters validated through element testing, literature review, and parametric studies. The earth pressure coefficients (K) and non-linear earth pressure distributions simulated using DEM align closely with those measured in centrifuge tests. For the wall rotation about the top and translation modes, DEM effectively captured the increase in earth pressure at shallow layers, attributed to the arching effect, as visualised by force chains and displacement vectors. The boundary effect was investigated by comparing the earth pressure distributions in DEM models under idealised plane-strain conditions and models with rough front and back boundaries. Results indicated that rough boundaries decreased earth pressures and increased particle rotations near the boundary, with this effect diminishing at a distance approximately 9 d(50).