路堤下带帽疏桩处治地基桩土荷载效应分析

Load effect of sparse capped-piles and soils in treating foundations under embankments

针对疏桩支撑路堤结构的作用特点,在一定简化的基础上,分别建立了上部路堤荷载转移分析模型和基底桩土相互作用计算模式,综合考虑上部路堤与疏桩地基的相互影响,根据基底位移连续条件,得出了一种计算带帽疏桩路基中桩、土荷载效应值的方法。通过工程实例现场实测结果对该计算方法进行了验证,与其它计算方法结果进行比较分析,结果表明采用该法计算的桩、土应力接近实测结果,说明该计算方法的合理性。同时,讨论了桩土荷载分担随填土高度、填土黏聚力和桩间距等因素的变化规律。

According to the characteristics of embankments supported by sparse piles, based on some simplifications, a load transfer mechanical model for embankments and a method for calculating the interaction between piles and soils are respectively established. In consideration of the interaction between embankments and foundations with sparse piles, a method is proposed for the load sharing between piles and soils with the compatibility of displacements on the bottom surface of embankments. The proposed method is validated by comparing the analytical solutions with the observed results of projects. The calculated results of the proposed method are also compared with those in the references. It shows that the analytical solutions are in agreement with the observed data, and the proposed method is reasonable. The factors which affect load sharing ratio of piles and soils, such as height of embankments, cohesion of fill and pile spacing, are analyzed.