Study on"Two zones"height of overlying rock in fully mechanized mining face of gently inclined coal seam
With the development of mining to the deep,the risk of mine water damage is gradually increasing.It is of great significance to accurately master the development height of the"two zones"of overlying rock in the goaf,namely the caving zone and the water-conducting fissure zone,for the prevention and control of water damage in the mine roof and the reasonable setting of water-separating coal(rock)column.Three methods,namely theoretical calculation,numerical simulation and water pressure test,are used to study the development height of"two belts"in overlying rock of No.020202 Face.The three methods were mutually verified.Finally,the maximum height of caving zone of the working face was 10.3 m,and the risk/production ratio was 4.12.The maximum height of the water-conducting fracture zone was 41.6m,and the fissure production ratio was 16.64.The results can provide scientific guidance for the safety of mine production.