Influence of shape on flying gangue migration in steeply dipping coal seam

The migration process of flying gangue has certain complexity and randomness in the working face of steeply dipping coal seam, so the accurate simulation of the migration process of flying gangue has important theoretical and practical significance for the safe and efficient mining in steep seam. Taking a large inclination thick coal seam in Shanxi coal mine as the research background, according to the spherical design, a numerical simulation test scheme covering all ellipsoidal flying gangue shapes was designed. A numerical simulation test was carried out on the migration process of flying gangue in the working space of 3D working face by using the energy tracking method, the trajectories of flying gangue can be obtained, and at any time of the curves of velocity, angular velocity and energy, and the influence of shape on the migration process of flying gangue was analyzed. The influence of the collision on the migration process of flying gangue was considered, and the migration process of the flying gangue without collision and with collision was simulated and compared. In order to verify the accuracy and feasibility of this method, the trajectories simulated by Rockyfor3D software were compared. The results show that the trajectory simulated by the method in this paper is basically consistent with the trajectory simulated by Rockyfor3D software, and the collision contact point between flying gangue and the floor of working face is more obvious. The migration of flying gangue is mainly affected by the shape of flying gangue, and the collision between flying gangue and the floor of the working face. In addition, the collision of flying gangue in the process of migration will cause the trajectory of flying gangue to change and the lateral migration distance to increase, resulting in the collision of flying gangue with coal wall, support column, scraper and other equipment in the process of migration, which will increase the difficulty of the protection of flying gangue. Applying the energy tracking method to the site can provide a certain theoretical basis for the prediction and protection of flying gangue hazards. © 2021, Editorial Office of Journal of China Coal Society. All right reserved.