Abstract：The double-shear unified strength theory is used to derive the formula of the Terzaghi¢s ultimate bearing capacity of foundation. The influence curves of the coefficient b are drawn. The solutions given can be flexibly used to calculate the ultimate capacity of all kinds of different special properties materials foundations. The solutions based on Mohr-Coulomb and double-shear strength theory are all the special cases of its solutions. The unified solutions are greater than that of the Mohr-Coulomb and double-shear strength theory，so the potential strength of materials can be fully applied to the relevant engineering foundation so as to obtain outstanding economical benefit.
