Fig. 2

Stress model of the roadway rock surrounded by non-uniform stress field. P1/MPa-Maximum principal stress, P3/MPa-Minimum principal stress, R-Radius of damage zone, a-Roadway radius, r and θ-Polar coordinates of any point in the damage zone.

Stress model of the roadway rock surrounded by non-uniform stress field. P1/MPa-Maximum principal stress, P3/MPa-Minimum principal stress, R-Radius of damage zone, a-Roadway radius, r and θ-Polar coordinates of any point in the damage zone.