柔性基础下群桩复合地基荷载传递规律及计算

复合地基沉降及荷载传递规律的研究是复合地基理论中一项非常重要的研究内容，然而对群桩复合地基的沉降及荷载传递规律的研究，在理论上很不成熟。在采用文1]推荐的竖向变形模式及文2]推荐的径向变形模式的基础上，利用弹性理论及桩-土位移协调条件建立了桩及桩周土的控制微分方程，并由此推导出了柔性基础下群桩复合地基加固区内桩及桩周土压缩量计算的解析式，同时得出了桩、桩周土中竖向应力及桩侧剪应力计算的解析式。通过算例将该方法所得结果与有限元结果进行了对比，同时也与模型实验结果进行了比较。算例及模型实验结果均表明：该方法对分析柔性基础下群桩复合地基的荷载传递规律及加固区的变形具有足够的精度，且该法计算工作量小，便于工程应用。

Load transfer law and deformation of the pile group composite foundation under the flexible foundation

Research of settlement and load transfer law on the composite foundation is a very important content in the composite foundation theory; then it isnt maturity to this kind of composite foundation studying of settlement and load transfer law on theory. In this paper, based on the vertical deformation model1] and the radial deformation model2], the control differential equations of pile and pile-surrounding soil are established by the elastic theory and the pile-soil displacement coordination condition. The analytical formulas calculating deformation of pile and pile-surrounding soil in the pile group composite foundation reinforcing area are derived under flexible foundation; at the same time the analytical formulas calculating the pile side shear stress and the vertical stress of pile and pile-surrounding soil are drew. For verifying feasibility of the method , the results acquired by this kind of method are contrast with the finite element method by way of calculating example. And also carrying on the model experiment. All results indicate: this kind of method has enough precision to analyzing load transfer law and deformation of the pile group composite foundation in reinforcing area under flexible foundation , it is simple to calculate, and is easy to engineering application.