Abstract: According to 4.2.4 of the GB 500072002 Code for Design of Building Foundation National Standard,for the preloadedconsolidated foundation,the shear strength parameters may be tested by consolidated-undrained test.Theoretically,the shear strength calculated by strength parameters measured by consolidated-undrained test is not always higher than that calculated from unconsolidated-undrained strength parameters,which might lead to the fact that the ground bearing capacity calculated from CU strength parameters is lower than that from UU strength parameters.The cases are analyzed when it occurs by applying the orthogonal design method and adopting the computational formula of ground bearing capacity and its coefficients of ground bearing capacity offered by the Code.