The flexible pile and the rigid pile, the gravel pile and CFG pile are arranged in a group as compound piles, which utilize their merits and avoid their shortcomings. Based on the study of the existing calculation methods for the bearing capacity of multi-pile composite foundation, the working behavior of loaded multi-pile composite foundation and the general influence of different construction methods to the bearing capacity of the soil are considered. The coefficient of the bearing capacity exertion of master piles, the coefficient of the bearing capacity exertion of minor piles, the coefficient of the bearing capacity exertion of the soil between piles and the coefficient of the bearing capacity improvement of the soil are introduced. The new step-by-step calculation method for the bearing capacity of multi-pile composite foundation is put forward. Through designed a high-rise frame structure with multi-type-pile composite foundation, the results show that the multi-type-pile composite foundation is more whole and possess stronger capacity of load transfer compared with single-type-pile composite foundation. It can satisfy the requirements of load bearing capacity and deformation under special foundation conditions.
