Abstract: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.