基于一维和三维固结挤土桩沉降时效计算分析

饱和软黏土地基中的挤土桩，施工引起的桩侧土体超孔隙水压力消散和竖向荷载引起的桩底土体固结是导致其沉降的主要因素。基于三维固结理论，研究了桩侧地基土再固结沉降的变化规律，并从桩-土相互作用的原理出发，结合边界条件，推导出了在桩侧地基土再固结沉降的作用下挤土桩沉降的计算公式。运用太沙基一维固结理论并采用分层总和法计算竖向荷载作用下桩底土体的沉降。提出了饱和软土中挤土桩沉降时效的计算方法。并对工程实例进行了计算分析，其结果符合工程实际沉降规律。

Calculation and analysis of settlement time-dependency of soil compaction pile based on one-dimensional and three-dimensional consolidations

The dissipation of excess pore water pressure of pile side soil caused by construction and the consolidation of subsoil caused by vertical load are major factors leading to the settlement of soil compaction pile in saturated soft clay. Changing rules of reconsolidation settlement of pile side soil are studied based on three-dimensional consolidation theory. The calculating formula of settlement of soil compaction pile is educed under reconsolidation settlement of pile side soil by using the interaction effect principle of pile and soil combining boundary condition. Terzaghi’s one-dimensional consolidation theory and layer-wise summation method are adopted to compute settlement of subsoil under vertical load. The calculating method is brought forward on settlement time-dependency of soil compaction pile in saturated soft clay. Engineering case is calculated and analyzed; and the calculating results accord with actual settlement rules.