Calculation and model test for pile-soil stress ratio of gravel pile composite foundation under embankment load

Working mechanism of gravl pile composite foundation under embankment loads is deeply analyzed.The system of embankment-pile-soil is simplified properly;the calculation model of pile-soil stress ratio is established;and the solving process of key parameters is given.The principle of minimum potential energy is adopted to deduce the formula of pile-soil stress ratio under embankment loads.Compared to the results which is observed in large-scale laboratory model test, the method put forward can satisfy the engineering requirement.Factors influencing the stress ratio are studied.The results show that the stress ratio is significantly affected by pile-soil modulus ratio and displacement ratio, while embankment height and embankment material less effect on it.The pile-soil stress ratio increases when the embankment height increases, it becomes stable when height comes to a fixed value;and it increases slightly when shear modulus of embankment fill increases.