柔性桩复合地基承载力数值计算

利用ANSYS有限元软件对柔性桩单（多）桩复合地基的承载力进行了数值计算，考虑的因素有：荷载、置换率、桩长径比和桩距，研究结果表明：随着荷载桩和长径比的增加，柔性桩单桩复合地基的桩身轴向应力峰值基本出现在距桩顶0.1倍左右桩长处，两者的变化均导致桩、土沉降有相同变化趋势；置换率的增加会导致桩承担更多荷载，但桩-土沉降变化趋势相反，不利于柔性桩复合地基的共同沉降；荷载和桩长径比对柔性桩多桩复合地基桩体承担的荷载贡献不大，但会导致桩-土有共同的变化趋势；桩距的变化能够导致柔性桩桩体承担的荷载有较大范围的变化，桩间土沉降较之桩沉降趋势更为明显，对柔性桩复合地基承载特性有一定的影响。

Numerical calculation for bearing performances of composite foundation improved by flexible piles

The bearing performances of the composite foundation improved by single-flexible-pile or multi-flexible-pile are calculated by using the FEM software ANSYS. Factors such as load, pile area replacement ratio, pile’s length-diameter ratio and pile’s distance-diameter ratio, have been taken into the consideration. Results show that in the composite foundation improved by single-flexible-pile, the distance of pile’s axial stress peak point to the pile’s top is about 0.1 time of pile’s length with the increasing of load and pile’s length-diameter ratio, while, the settlement tendency both pile and soil are similar. The pile’s bearing performance is increased with the increasing of pile area replacement ratio; but the settlement tendency both pile and soil are opposite, which affects the composite foundation’s settlement. In the composite foundation improved by multi-flexible-pile, the changes of load and pile’s distance-diameter ratio have no influence on loads shared by piles and result in the same tendency for the pile and soil’s settlement. The change of pile’s distance-diameter ratio has more influence on loads shared by piles and results in the soil’s settlement more than the piles’ one, which has the obvious influence on the composite foundation’s bearing performances.