Abstract: Reasonable determination of bearing capacity of foundation soils is a most important part of making full use of the bearing capacity of foundation soils. This paper analyzes the method suggested by the present code, and points out some shortcomings such as the corresponding relation between safety factor and settlement value is not clear and definite. In the practical application, the determination of the bearing capacity of stiff soil or low compressive foundation soils is usually conservative; while the soft soil, high compressive foundation soils and large-size foundation will at risks due to large settlement. Thus, a new solution method is proposed in this paper. That is, computing strength and deformation of a specific foundation by using strength and deformation parameters. Then, according to the double controlling method, the settlement requirement and strength safety factor requirement of the foundation soils, the bearing capacity of the foundation soils can be determined. Finally, by obtaining specific safety factor, settlement value and more reasonable bearing capacity of foundation, it is helpful to make better use of the bearing capacity of foundation soils in engineering design. At the same time, safety and engineering value are reached. When the in-situ plate loading test hasn’t reached limit state, one suggestion on determining strength parameters is using maximum test value. The simple double controlling principle is also suggested in this paper. A case study is presented to make application easier.

Key words: bearing capacity of foundation soils, double controlling method, tangent modulus, plate bearing test