碎石桩软土复合地基整体抗剪强度研究

振冲碎石桩作为散体材料桩与周围的软土形成的复合地基，同钢筋混凝土桩、钢管桩等刚性桩形成的复合地基在工作原理、承载力分析等方面存在着本质的不同。与刚性桩相比，碎石桩作为垂直排水通道，能够加快周围软土的排水固结，提高桩间土的整体强度。同时碎石桩自身的承载力发挥又取决于周围土体的侧向支撑作用。如何确定碎石桩复合地基的整体抗剪强度对于发挥碎石桩的作用至关重要。以港珠澳大桥香港口岸人工岛项目碎石桩的工程应用为例，对比碎石桩软土复合地基整体抗剪强度计算的异同，通过数值模拟和现场监测等手段对参数取值进行分析，对今后类似工况条件下碎石桩复合地基的抗剪强度计算具有指导意义。

Overall shear strength of stone column-soil composite ground

There are essential differences between the composite grounds improved by stone columns and by rigid piles,such as reinforced concrete piles,steel-pipe piles and other rigid piles.The voids of the stone columns can act as vertical drainage channels and accelerate the consolidation of the surrounding soft soil resulting in the improvement of the ground strength.Meanwhile,the improvement effect of the stone column depends directly on the lateral support of the surrounding soil.How to accurately determine the overall shear strength of stone column-soil composite ground is the key task to make full use of stone columns.Taking Hong Kong boundary crossing facilities-reclamation works for example,we compare different calculating methods for the overall shear strength of the composite ground,and carry out some analyses of the parameters using the finite element analysis and in-situ monitoring.This study has significant effect for the calculation of overall shear strength of the composite foundation under similar conditions.