Experimental study on grouting filling in goaf under thick hard magmatic rock
Aiming at the problem of large-area hanging roof of thick hard magmatic rock formed by coal seam mining,taking the local magmatic rock intrusion in Haizi Mine as the research object,the development characteristics of surface rock movement and separation layer under magmatic rock mass were analyzed,and the grouting filling test in underground goaf was carried out.The research results showed that after the mining of the working face in the second mining area of Haizi Mine,the measured maximum surface settlement was only 487 mm,which was far lower than the surface settlement caused by mining in the non-magmatic rock development area.The magmatic rock mass was not broken,and there was a separation space between the goaf and the magmatic rock mass.Through the implementation of ground drilling grouting in the caving zone,fracture zone and separation zone,the artificial column was constructed,and the high stress concentration phenomenon caused by the large area hanging roof of the thick hard magmatic rock mass was eliminated.
thick hard magmatic rockgoafgrouting fillingseparation layer