Concrete-cored sand-gravel(CCSG) pile composite foundation is a new multi-type composite foundation. By incorporating the logarithm models of e-lgσ and e-lgk of soil

the characteristics of the nonlinear variation in the soil’s compressive modulus and the soil’s permeability during consolidation are considered. Based on equal strain assumption

the analytical solution is developed for CCSG pile composite foundation

which combined with itself characteristics and stress concentration effects. The existing consolidation solutions of sand drain foundation and gravel pile composite foundation under nonlinear characteristics of soil are special cases of this solution. Curves of the average consolidation degree of the composite foundation were observed based on the theoretical formula under the variation of various non-dimensional parameters such as the ratio of pile-soil modulus and soil compression index and penetration index

and load increment. The analytical results show that the average degree of consolidation in terms of stress is not equal to that in terms of deformation; in addition

the average degree of consolidation in terms of stress is greater than that in terms of deformation; the nonlinear characteristics of soil have a large affect on consolidation. The analytical solution is finally validated with the actual measurement data.