Study on deformation and failure law of bolt-mesh support roadway under roof impact load

In order to study the deformation and failure law of bolt-mesh support roadway under roof impact load, taking 250104 transport roadway of Huating Coal Mine as background, FLAC^3D was used to analyze the variation characteristics of stress, deformation and plastic zone of surrounding rock of bolt-mesh support roadway under different impact load wave velocities, angles and offset distances. The results show that: under the impact of roof load, the plastic zone of roadway roof and rock mass on both sides will gradually expand to upward and both sides, and its maximum displacement will increase exponentially; with the increase of the wave velocity of the roof impact load, the maximum displacement of the roadway roof and two sides will gradually increases exponentially; with the increase of impact angle of roof impact load, the maximum displacement of the roadway roof and two sides presents an “S-shaped” growth curve, and the impact angle of 90° has the most adverse impact on the stability of the surrounding rock of the roadway with bolt-mesh support; with the increase of the impact offset distance of roof impact load, the maximum displacement of roadway roof and impact side rock will increase first and then decrease. When the impact offset distances is equal to 5.0 m, it will pose the greatest threat to roadway safety.