Abstract
The mechanisms of two-dimensional specific cutting resistance and steady excavating force for weak rock mass have been analysed by means of the failure criterion of rock materials. As the results, the specific cutting resistance could be estimated by Eqs. (11), (12) from the unconfined compressive strength, radial compressive strength, assuming that the shear failure develops on the whole linear slippage line on which the normal stress distributes to the power of 0.30 and the steady excavating force could be estimated by Eq. (28) from the unconfined and radial compressive strength, assuming that the shear failure develops on the logarithmic spiral and linear line on which the normal stress distributes to the power of 1.79. The steady cutting force could be expressed by the function of specific cutting resistance, depth of excavation and rake angle of the blade.
