桩垛在悬臂桩基坑工程中的分析研究

Role of Pile Cap in the Cantilever Piles as the Deep Excavation Supporting Structure

采用有限元数值分析方法研究了桩垛在悬臂桩基坑工程中的作用效果。结果表明:①桩垛对基坑的长边变形起到了较好的控制效果,桩垛具有协调基坑变形的作用;②桩垛改善了悬臂桩的变形特性,桩垛起到的作用类似于在桩顶处增设水平刚度的效果;③桩垛的桩数越多对桩顶水平位移控制效果越显著;④桩垛间距B越小,桩身弯矩越大;桩垛的桩数越多,桩身弯矩越大;推荐桩垛采用的桩数为单或双根桩。相关结论可为类似工程提供借鉴。

The role of pile cap in using the cantilever piles at the deep excavation supporting structure is evaluated by the finite element method.The following results are obtained:1)the pile cap has a significant effect in controlling the excavation deformation at the longer side and presence of the pile cap makes the excavation induced deformation more compatible.2)Since the pile cap increases the lateral stiffness at the top of piles so that the deformational characterization of the cantilever supporting structure has improved.3)Better lateral deflections can be obtained by increasing the number of pile caps in the supporting system.4)The smaller pacing between the pile caps,the larger bending moment in the pile;the greater number of pile caps,the larger the bending moment in the pile.