Finite element modelling of rolling dynamic compaction

Abstract

Rolling dynamic compaction (RDC) utilises a heavy (6 to 12-tonne) non–circular module (impact roller) that pivots about its corners as it is towed, causing the module to fall to the ground and compact the underlying soil dynamically. This paper presents the development of a transient, non–linear finite element (FE) model of the Broons BH–1300 4–sided 8 tonne impact roller, undertaking multiple passes, using LS–DYNA, validated against a field trial and observations presented in the literature for the same coarse–grained material. The results of the numerical analyses demonstrate that the FE model provides reliable predictions of the 4-sided roller as observed in the field. Thus, the use of this FE model may provide high resolution insights into the capability of the impact roller, namely in predicting the settlement and densification of an underlying coarse-grained material. The FE model demonstrates significant soil improvement directly beneath the width of the roller to approximately 1.2 m depth. Residual improvement is shown to extend to approximately 2.5 m depth and 1.25 m laterally.