Abstract: In view of the problems existing in the design of multi-columns composite foundation, such as the large subject of the estimation results due to the empirical value to the bearing capacity correction coefficient of soils and columns, as well as the large difference between the estimated and the measured settlement values when the composite compression modulus is used in the improvement area for the composite foundation. By using the column-soil deformation conformity method, the real column-soil stress ratio and bearing capacity correction coefficient are obtained theoretically, which avoids the defect of determining the bearing capacity correction coefficient subjectively and makes the settlement and bearing capacity estimation of the composite foundation more accurate and scientific. In the view of the problems that the composite foundation cannot be formed and the building foundation and the natural ground are separated due to the qualitative design of the composite foundation cushion layer, a quantitative design method of the cushion layer is proposed according to the formation conditions of the composite foundation, which avoids the defects of qualitative design.

Key words: Composite Foundation, Deformation Conformity, Settlement, Bearing Capacity, Cushion Layer