Taking an engineering instance as background

the deformation characteristics and working mechanism of the cement flyash gravel (CFG) pile composite foundation are analysed with finite difference method; and the composite effect of the pile to work with soil and the effectiveness of cushion are also simulated. It is indicated that the bearing capacity of ground can be enhanced effectively through the CFG plies with some stiffness which are driven into the soil; the pile stress acts mainly from the top to the middle of the pile shaft; and the piles of which the lengths extended applicably can help to control the deformation of ground foundation; and the cushion is beneficial to adjust the stress distribution. The results can be for reference in similar projects.