Discrete element modelling of the 4-sided impact roller

Abstract

Rolling dynamic compaction (RDC) is a ground improvement technique, which involves towing a non-circular module behind a tractor to achieve soil compaction. When compared against conventional static and vibratory compaction techniques, RDC is capable of compacting thicker layers of soil and at a faster operating speed. This study validates the developed numerical scale model against a field study using the full-size RDC module. Numerical results were compared with the field data in four aspects namely, displacements at the ground surface, and at depths of 0.7 and 1.1 m, pressures at 0.7 and 1.1 m depths, energy delivered by the RDC module into the underlying soil, and the depth of improvement. It is concluded that, numerical results are in good agreement with the field data. This paper also proposes that pressure results are an imperfect indicator to assess the optimum number of RDC passes, whereas, ground settlement is recommended since it better reflects ground improvement due to RDC and it has a clear relationship with the number of passes.