水泥土搅拌桩复合地基桩土应力比的解析算法

Analytical calculation of pile-soil stress ratio of cement-soil mixed pile composite foundation

为了分析路堤荷载作用下水泥土桩复合地基桩土应力比问题,提出改进的单元体位移模型。通过假设路堤填土的竖向位移模式和土工格栅的变形方程,分别推导路堤填土的竖向应力以及土工格栅作用于桩顶的拉应力;根据桩顶处竖向受力平衡,求得桩顶应力;通过假定地基土满足Winkler地基模型,求得桩间土应力,从而得到桩、土应力比的计算公式。通过与实测工程结果比较,证实了该公式的合理性,这对路堤下复合地基设计具有一定的参考价值。

An advanced unit model was put forward to analyze the pile-soil stress ratio of cement-soil pile foundation under embankment load.Based on the assumed vertical displacement of embankment fill and the assumed deformation formula of geogrid,the vertical stress of embankment fill and the tensile stress of geogrid on the top of pile were deduced.According to the balance of vertical loading on the top of pile,the vertical stress of the top of pile was established.The vertical stress of surrounding soil was derived by assuming that surrounding soil conformed to Winkler model,and the calculation formula of pile-soil stress ratio was established.The rationality of formula is confirmed by comparison with the measured data,and it has reference value to the design of composite foundation under embankment.