School of Civil and Resource Engineering, University of Science and Technology Beijing
Research Center for Rock Burst Pre-vention and Control, Shandong Energy Group Co., Ltd.
Zhaolou Coal Mine, Yanzhou Mining Group Co., Ltd.
Coal Mine Rockburst Prevention and Control Research Center, Yanzhou Mining Group Co., Ltd.
School of EarthScience and Engineering, Hohai University

应力加载型冲击地压是深厚表土综放采场特有的冲击地压类型,其发生机理尚不清晰,导致煤矿面临此类型冲击地压时无法有效防治甚至发生严重事故。以巨野煤田赵楼煤矿 3304(超前100 m) 长时间 (持续 38 d) 冲击预警为工程背景,采用相似材料试验、理论分析、数值模拟、现场实测等方法,研究了深厚表土综放采场应力加载型冲击地压的发生机理,得出了以下结论:由模拟试验和理论分析提出了深厚表土综放采场的覆岩空间运动特征,基于承载基岩初次破断时厚表土的成拱性和延时加载性,推导了厚表土垮落拱和压力拱的轮廓表达式,建立了深厚表土综放采场走向覆岩传递应力估算模型。揭示了深厚表土综放采场应力加载型冲击地压机理:当承载基岩达到悬露极限发生断裂回转时,厚表土层运动下沉形成土压力拱结构,其上覆巨厚表土层自重通过拱脚传递至煤层中,导致煤壁前方大范围煤层应力在短时间内大幅度持续升高,容易诱发应力加载型冲击地压。数值模拟结果表明深厚表土综放采场承载基岩断裂后,厚表土呈现由下至上渐进式破碎、垮落的运动特征,采场以岩、土接触面为界形成 2 个压力拱,表土压力拱传递的表土自重导致煤壁前方大范围煤层应力高度集中。现场实测表明应力加载效应发生后采场动载释放水平较低且呈现固定位置的微震集中带,土压力拱的形成将限制表土层快速下沉,工作面位于土压力拱的支点区域进行回采工作,当工作面推过该支点加载区域后,土压力拱破坏导致采场地表整体大幅度下沉。设计并实施了深厚表土综放采场应力加载型冲击地压的防治方案,包括井下地面联合监测预警、围岩高强度钻孔弱化、显现区域支护体系补强、“监测−卸压”临界推速控制。

The stress-loaded rockburst is a unique type of rockburst that occurs in some fully mechanized top-coal cavingstopes with deep thick overburden, its occurrence mechanism is still unclear, leading to the failure to effective preventionand even serious accidents when the coal mine is faced with this type of rock burst. This study focuses on the stress-loadedrockburst that occurred in the 3304 fully mechanized top-coal caving face of the Zhaolou Coal Mine, Juye Coalfield,which lasted for 38 days and had a large range of impact warning (100 m ahead). Through material tests, theoretical analysis, numerical simulations, and field measurements, the study investigates the occurrence mechanism of stress-loadedrockburst in the fully mechanized top-coal caving stopes with deep thick overburden. The study proposes the spatial movement characteristics of overburden in the fully mechanized top-coal caving stopes with deep thick overburden through simulation tests and theoretical analysis. The contour expressions of collapse arch and pressure arch of thick overburden arederived based on the arching property and time-dependent loading property of thick overburden when the bearing bedrockis first broken. An estimation model for the transfer stress of overlying strata along the strike of the fully mechanized topcoal caving stopes with deep thick overburden is established. The mechanism of stress-loaded rockburst in the fully mechanized top-coal caving stopes with deep thick overburden is revealed through the study. When the bearing bedrock reachesthe hanging limit and breaks and rotates, the thick overburden moves and sinks to form an earth pressure arch structure.The weight of the overlying thick overburden is transferred to the coal seam through the arch foot, resulting in a largerange of coal seam stress in front of the coal wall that continues to rise in a short time, which can induce stress-loadedrockburst. The numerical simulation results show that after the bearing bedrock of fully mechanized top-coal caving stopeswith deep thick overburden breaks, the thick overburden presents the movement characteristics of progressive breakingand collapse from the bottom to the top. The stope forms two pressure arches with the rock and soil contact surface as theboundary. The weight of the overburden pressure arches causes the high concentration of stress in the large range of coalseams in front of the coal wall. The field measurement shows that the dynamic load release level of the stope is low afterthe stress loading effect occurs, and the micro-earthquake concentration zone is fixed. The formation of the earth pressurearch will limit the rapid subsidence of the topsoil. The working face is located in the fulcrum area of the earth pressurearch for mining. When the working face pushes over the fulcrum loading area, the destruction of the earth pressure archwill lead to the overall large subsidence of the stope surface. The study proposes a prevention and control plan for thestress-loaded rockburst in the fully mechanized top-coal caving stopes with deep thick overburden, including undergroundground joint monitoring and early warning, high-strength borehole weakening of surrounding rock, reinforcement of support system in the exposed area, and “monitoring and pressure relief” critical pushing speed control.

国家重点研发计划资助项目(2022YFC3004604,2022YFC2903803);中国科协青年人才托举工程资助项目(2021QNRC001)

张翔,朱斯陶,姜福兴,等. 深厚表土综放采场应力加载型冲击地压机理[J]. 煤炭学报,2023,48(5):2092−2105.

ZHANG Xiang,ZHU Sitao,JIANG Fuxing,et al. Mechanism of stress-loaded rockburst in fully mechanizedtop-coal caving stope with deep overburden[J]. Journal of China Coal Society,2023,48(5):2092−2105.