微型钢管桩芯-旋喷桩复合桩基的计算分析与数值模拟研究

摘要

在φ600旋喷桩上部中心位置压入一定长度的Φ108微型钢管,形成微型钢管桩芯-旋喷桩复合桩基(简称复合桩).对复合桩静载荷试验的荷载-沉降曲线进行了区段分析,确定了其极限承载力实测值为1080 kN.对该复合桩基4种破坏模式下的抗压极限承载力进行计算分析对比后发现,复合桩芯底位置处发生水泥土压碎破坏的可能性最大,抗压极限承载力最小,为1 125 kN.通过数值模拟对复合桩的极限承载力,桩侧摩阻力分布,破坏模式下的塑性变形,荷载分担比等进行了分析.%Press Φ108 mini steel pipe with a certain length in the upper center of φ600 chemical churning pile to form mini steel pipe pile core-chemical churning pile compound pile foundation shorted compound pile.This paper analyzes the load-settlement curve of static load test of the compound pile in section and determines the actual measured value of its ultimate bearing capacity is 1 080 kN.By calculating,analyzing and comparing the ultimate bearing capacity of the compound pile foundation under four failure modes,it is found that the cement soil crushing failure is most possible to occur at the bottom of the pile core,with the minimum pressure resistance ultimate bearing capacity of 1 125 kN.The ultimate bearing capacity of the compound pile,lateral friction distribution,plastic deformation under failure mode and load sharing ratio are analyzed through numerical simulation.