Effects of the axial in situ stresses on the zonal disintegration phenomenon in the surrounding rock masses around a deep circular tunnel

A new non-Euclidean model in which effects of the axial in-situ stress with arbitrary value on the zonal disintegration phenomenon in the surrounding rock masses around a deep circular tunnel is taken into account is established. The total elastic stress-field distributions of the surrounding rock around a deep circular tunnel including effects of the axial in-situ stress were given out. The strength criterion of the deep rock masses is applied to determine the occurrence of disintegration zones. The numerical computation was carried out. It is found from numerical results that number and size of fractured and nonfractured zones are sensitive to the axial in-situ stress, tangential, radial and axial normal stress, the intermediate principal stress coefficient and the rock mass rating classification RMR.