Study On Rock Burst Prevention And Control Technology In Hard Roof Mining

Since the uncovering of coal in July 2014 in Gaojiapu coal mine,there have been frequent rock burst disasters due to the influence of buried depth,hard roof and other factors,which are reflected in the rapid bulge of the floor,the sudden bulge of the two sides,the subsidence of shoulder socket and roof,the fracture of anchor rod(cable),accompanied by the loud sound of coal cannon,the situation of rock burst disasters is very serious.Especially in February 3,2017,September 27,2017,August 16,2018 and November 4,2018,a number of rock burst events have had a significant impact on mine safety production.Therefore,this paper takes Gaojiapu coal mine 102 working face as the research object,and theoretically analyzes the impact risk factors,overburden structure characteristics,dynamic and static load sources of 102 working face under the condition of hard roof.The results show that the overburden structure is O-X structure,the static load source of working face 102 is self weight,support and structural stress,and the dynamic load source is overburden movement and fault slip.The impact is easily induced by the superposition of multiple force sources.Therefore,the area of impact risk of working face 102 is mainly distributed during the period when the working face passes through the cut hole and sees the square.At the same time,based on the microseismic data of 102 working face during mining under the condition of hard roof,the microseismic distribution and evolution law of 102 working face are obtained.The microseismic events caused by mining in 102 working face are mainly events with energy less than 103J,and have certain correlation with mining speed and mining height.The faster the mining speed and the higher the mining height,the more intense the microseismic activity.Finally,combined with the characteristics of 102 working face,the monitoring and control technology of rockburst in 102 working face is obtained.The main measures include reasonable design of section coal pillar width,large diameter drilling,roof blasting and coal blasting.Through the above measures,the impact risk level during the mining period of the working face is reduced,the mine pressure is relatively stable,and the safe mining of the working face is ensured.The research results of this paper can effectively guide the safety production of 102 working face.At the same time,it also provides theoretical support and technical guidance for the anti scour design of adjacent mines or similar working faces.