Rock burst prevention technology for hydraulic fracturing on thick and hard roof surface
In response to solve the difficulty of effectively eliminating roof rock burst in deep coal mines by only using local pressure relief measures,the principle of inducing rock burst by the superposition of dynamic and static loads on thick and hard roof was analyzed.A technology for preventing rock burst at the source of the roof force source structure through ground hydraulic fracturing was proposed.Based on the mining and geological conditions of No.4107 working face at Wenjiapo Mine,ground hydraulic fracturing tests were conducted on thick and hard roofs.The on-site test results show that a thick and hard roof suspension without collapsing provides a static load foundation,sudden breakage provides an increase in dynamic load,and the combination of dynamic and static loads triggers impact initiation beyond the critical load.Ground hydraulic fracturing can cause thick and hard roof fractures,and the formation will largely crack under the pressure of fracturing fluid.The length of the ground fracture is 301～332 meters,the height of the fracture is 50～58 meters,and the width of the fracture is 50～60 meters.Artificial release layer reduces the strength and integrity of thick and hard roofs,making long beams shorter and large blocks smaller.Ground hydraulic fracturing technology breaks the roof,which reduces the stress concentration level of the surrounding rock of the roadway and ensures smooth mining of the working face.
thick and hard roofpower source structureground fracturingsource controlrock burst
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