基于模型试验的静压群桩引起的土体变形分析

Analysis of soil deformation in jacked pile group based on the model test

以往对沉桩挤土效应的研究主要集中于单桩或双桩,对群桩挤土效应分析较少。基于室内模型试验,分析了群桩压入软土后土体的变形情况,得到了沉桩过程中及压桩后土体侧向位移、竖向变形和土层表面隆起变化的规律。认识到单桩侧向挤土位移随着距桩边距离的增加而以近似对数规律衰减,群桩压入后土体水平侧移和地表隆起是不断累积的,存在着已压入桩的遮帘作用,而且桩施工顺序对土体位移起到了关键作用,应该在实际工程中得到重视。

In the past the study of squeezing effect during pile driving focused on the single or double pile, but little on the pile group. Based on the model test, soil deformations were analyzed when the pile group were driven; then the soil lateral displacement, vertical deformation and the law of soil surface heave were obtained. It is concluded that as the distance to the pile edge increasing, the soil compaction displacement of the side surface of pile is logarithmicly decaying; the soil horizontal displacement and land surface heave are accumulated continuously; but there are sheltering effects after pressing pile, constructing order of pile plays a key role in the soil displacement; so it should be recognized in actual projects.