Compaction-Induced Stress in Geosynthetic-Reinforced Granular Base - A Discrete Element Model

A discrete element method (DEM) model was created to simulate the development of compaction-induced stress in a granular base course, with and without geogrid reinforcement. The granular base course was modelled as a mixture of poorly graded balls and clumps. The geogrid was modelled as a series of equally spaced balls which interact with each other through a long-range attraction. The long-range interaction contact was also used to simulate a deformable soft subgrade layer. The compactor was modelled as a solid cylinder rolling at a constant speed. The numerical result showed that a single pass of roller compaction produced significant compaction-induced stress in the granular base course. Reinforced base course gained more compaction-induced stress due to the residual tensile stress developed in the geogrid. The residual tensile stress increased significantly after the first compaction pass. Subsequent compaction passes helped to improve the uniformity of the residual stress in the geogrid.