Bearing capacity mechanism of vibro-replacement stone columns in coral sand with particle breakage
摘要
Coral sand presents significant challenges to ground improvement design due to its high void ratio, high compressibility, and particle breakage. Traditional bearing capacity theories for vibro-replacement stone columns are typically based on the assumption of soil shear dilation or constant volume. However, these assumptions fail to account for the particle breakage-induced energy dissipation and volume contraction characteristic of coral sand under high stress, leading to significant discrepancies in calculation results. Based on an analysis of the physical and mechanical properties and the breakage mechanism of coral sand, this paper proposes a novel three-step method for in-situ porosity measurement. Furthermore, a dual-mechanism coupling model, incorporating both energy-equivalent additional confining pressure and breakage-friction coupling, is proposed. By introducing the particle breakage energy dissipation coefficient