路堤下复合地基桩、土应力比分析

由于路堤由填土等散体材料组成，路堤下复合地基桩与桩间土之间的沉降不一致，导致填土内部出现相对垂直位移，应力状态发生变化。计算路堤复合地基桩、土应力比的方法及计算参数均与刚性基础下的复合地基不同。通过对复合地基上部填土的力学分析，推导出一个求解桩顶平面处的桩、土应力比的公式。该公式表明桩顶处桩、土应力比的大小与复合地基置换率，桩顶处桩，土沉降差，填土厚度，填土弹性模量等关系密切。最后，利用一个工程实例证明该公式的正确性。

ANALYSIS ON PILE-SOIL STRESS RATIO FOR COMPOSITE GROUND UNDER EMBANKMENT

The calculation method for the pile-soil stress ratio of composite ground under embankment and the calculation parameters are different from those of composite ground under rigid foundation due to the different settlements of pile and soil of composite ground, which results in vertical relative displacement in fill column and change in the stress state. An equation to solve the pile-soil stress ratio is established by mechanics analysis on the fill column above the composite ground under embankment. The observed results in an engineering project prove the availability of the equation. It is shown through the equation that the pile-soil stress ratio of composite ground under embankment is affected strongly by such factors as replacement ratio of composite ground, difference of settlement between pile and soil at the level of top of pile, height of fill, elastic modulus of fill.