Research on surrounding rock control technology of fully-mechanized top coal caving mining face end under mining influence

Aiming at the problem of influence of mining head at the top of fully-mechanized caving face that appeared rib spalling ,roof fall accident and advanced terminals support difficult to move.Using FLAC3D to study the failure process of the surrounding rock at the top of the fully-mechanized caving face .A method is put forward to reinforce the anchor rope and to change the stress distribution of the surrounding rock at the face end terminals.The method transferred stress concentration area of surrounding rock to the deep part and promoted surrounding rock stability at the head of face end.Field observation results show that when the surrounding rock is not influenced by mining, the stress concentration region is located at the top corner of the face end.The maximum stress is 28.9 MPa; when the surrounding rock is influenced by mining, the stress concentration area of the surrounding rock is transferred to the shallow part at the apex angle of the tunnel.The surrounding rock can not be effectively controlled and appeared rib spalling and roof fall accident; after under holed and reinforced the anchor rope, the stress concentration area is transferred to the deep part at the top roof corner of the face end.The surrounding rock is effectively controlled.The study results shows that using the method of under holed and reinforced the anchor rope at terminals head can avoid rib spalling, roof fall accident when the surrounding rock is influenced by mining.It ensured the favorable movement of leading face end support.