Abstract

This thesis presents an axisymmetric numerical model to simulate Dynamic Compaction of a thin subgrade layer overlying a deep deposit of various stiffness levels. The compaction effort is applied by means of impact energy on the ground and modeled as a transient loading having a constant frequency level with different amplitude values depending on the energy level used. On the light of the numerical model results obtained, it can be reported that the presence of weak deposit significantly affects the compaction level of the subgrade. The results depend on the thickness of the subgrade layer, stiffness of the underlying deposit and the energy level used. The energy consumed to compact the subgrade layer and further the energy dissipated to the lower deposit were measured, and accordingly, the level of compaction for a given soil/load/geometry conditions was predicted. Design procedure was given for practicing use. Designer may consider alternatives for undesirable cases such to improve the lower layer before compaction using other methods of soil improvement.