In order to accurately calculate the settlement of rigid pile composite foundation under embankment load

an analysis method is provided based on vertically linear development model of friction coefficient between the inner and exterior soil columns in the embankment supported by the composite foundation

as well as distribution mode of pile-soil relative displacement and development coefficient of skin friction on the pile. Thus

considering soil arching effect in the embankment and coupling characteristics of vertical load transfer between the embankment and improved zone

pile-soil stress ratio

differential settlement between pile and soil

and settlement of the improved zone are all derived by the principle of static equilibrium of a microelement in the embankment-foundation system. The proposed method can quantitatively reflect the dominant influence factors

such as height of embankment

internal friction angle and cohesion of the filling and soft foundation soil

pile length

pile diameter and pile spacing. Analysis results of examples show that relative error between the calculated and measured values is less than 15%. Pile length has non-linear effect on the settlement of the improved zone

while area replacement ratio

cohesion and internal friction angle of the foundation soil have linearly negative effect on the settlement. Moreover

the settlement is more sensitive to internal friction angle than cohesion.