(1. Coal Mining Branch, China Coal Research Institute, Beijing 100013，China；2. CCTEG Coal Mining Research Institute，Beijing 100013，China；3. Coal Mining and Designing Department，Tiandi Science and Technology Co.，Ltd.，Beijing 100013，China；
4. State Key Laboratory for Intelligent Coal Mining and Strata Control，Beijing 100013，China)
Abstract：The key of roof water inrush prevention and water resources protection of coal mine is to control the height of the water conducted fracture zone and reduce mining disturbance of the overlying aquifer. Based on the current research status of overburden damage control technology and pre-cracking weakening control of ground pressure in coal mine，a method to control overburden damage by actively weakening the hard rock layer is proposed. This method does not affect mining efficiency and coal resource recovery rate. Combined with similar simulation，theoretical analysis and numerical simulation analysis，the mechanism of pre-cracking weakening thick-hard roof to control the height of water conducted fracture zone was studied. According to the numerical simulation results，a method for determining the pre-cracking hard overburden under the aquifer is proposed. The results of the study indicate that：Due to the hard rock disintegrate into larger pieces during mining，and after mining，these broken pieces will be neatly piled up in goaf，therefore the bulking coefficient of hard roof after mining is smaller than normal roof. Pre-cracking can increase the bulking coefficient of hard stratum，reduce the subsidence of overlaying strata，and thus reduce the height of water conducted fractures zone. The response of the overlying strata to mining damage varies significantly under different pre-cracking for hard rock layers in different layer positions. Therefore，the selection of the pre-cracking position will directly determine whether pre-cracking weakening control of the water conducted fracture zone height is effective. The simulation results indicate that pre-cracking the middle thick hard rock layer and pre-cracking the middle and low level rock layers simultaneously can effectively control the height of water conducted fracture zone. The study results provide a new technical path for the safe，efficient，and green mining of coal resources under aquifer.
张玉军1，2，3，4，肖 杰1，李友伟1，宋业杰2，3. 坚硬主控覆岩预裂弱化控制导水裂缝带高度机制研究[J]. 岩石力学与工程学报, 2024, 43(S1): 3363-3373.
ZHANG Yujun1，2，3，4，XIAO Jie1，LI Youwei1，SONG Yejie2，3. Mechanism study of thick-hard overburden pre-cracking weakening to control the height of water conducted fracture zone. , 2024, 43(S1): 3363-3373.
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2024, Vol. 43 
