NUMERICAL SIMULATION OF INFLUENCE OF LOCKED-IN STRESS DIRECTION ON BRAZILIAN DISC TEST

In order to reveal the influence of locked-in stress on the stress distribution and rupture evolution process of Brazilian disc, a two-dimensional numerical simulation of locked-in stress on the rupture process of Brazilian disc in different directions was carried out. The region of locked-in stress is equivalent to a closed inclusion distributed in the rock mass. The disk distribution of locked-in stress in different directions and the formation and propagation process of cracks were investigated. The results show that the change of local stress in the locked-in stress area is significantly higher than that in the non-residual stress area, and the local stress in this area gradually decreases to less than the surrounding stress with the loading process. By comparing the maximum Mise stress in loading process with or without locked-in stress, it is found that the maximum Mise value is 20.78 MPa when the angle between locked-in stress and loading direction is 0°. When there is unlocked in stress and the direction of locked-in stress is 0°, the center of the disk cracks; when the direction of locked in stress is 30°, 60° and 90°, the crack zone of the disk tilts and several short inclined cracks appear, and the disk does not crack at the center.