The geosynthetic-reinforced cushion in pile-supported embankment works as a beam or plate
taking the characteristic of PCC pile composite foundation into account
therefore the reinforced cushion is considered to be an elastic thin sheet for calculation; and the formula of differential settlement between pile and soil has been drawn by using the thin sheet small deflection theory. On the basis of the compatible deformation between cushion and landfill
the methods of calculating the height of uniform settlement plate in landfill and stress ration between pile and soil have been got
but the compression of cushion material has been ignored. Finally
the comparison between calculated result and measured result shows that the formulas are acceptable. This method is also adaptable for other rigid pile-supported embankment.