考虑降水的基坑开挖卸荷对坑底桩的影响  

Research on effect of dewatering and excavation on pile

作　　者：李镜培[1,2] 王笑[1,2] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下系,上海200092

出　　处：《工程勘察》2011年第9期5-8,共4页Geotechnical Investigation & Surveying

基　　金：上海市科委"科技创新行动计划"资助项目(No.09231200900)

摘　　要：降水与深基坑开挖卸荷是影响坑底工程桩工作性状的重要因素,应用有限元分析软件ABAQUS建立基坑开挖二维模型,综合考虑了降水及卸荷对坑底工程桩的影响,得出如下结论:降水能有效减少开挖引起的工程桩回弹及坑底土体回弹;前期降水增大了桩身轴向压应力而开挖卸荷使桩身拉应力逐渐增大;降水导致地基固结沉降从而使桩侧产生负摩阻力,降水深度越大,负摩阻力越大。考虑降水情况下桩的受力变形均小于不考虑降水情况下,因此,降水对减少坑底回弹及桩身受力变形有积极的作用。Both the dewatering and deep excavation have a significant influence on the piles.Based on the general commercial software ABAQUS,2D models considering the effect of dewatering and excavation were established.The results show that during dewatering the bottom rebound was reduced effectively and the axial compressive stress of piles increased.The tensile stress of pile increased due to excavation.The consolidation settlement of soil because of dewatering made the negative skin friction of pile increased.The deformation and force of pile considering dewatering are less than that without considering dewatering,therefore dewatering plays a positive role in the reduction of the deformation and force of pile.

关 键 词：降水开挖 坑底回弹 负摩阻力 坑底桩 

分 类 号：TU463[建筑科学—结构工程]