State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University
Research and DevelopmentCentre, Jinneng Group Co., Ltd.
School of Mines, Taiyuan University of Technology
School ofMines, China University of Mining and Technology

坚硬顶板特厚煤层开采采场空间大,矿压作用复杂,致使采场强矿压作用机理不清,并缺乏针对不同层位坚硬顶板的多点控制技术体系,必须在更大采场空间范围内研究坚硬顶板控制的新理论和新技术体系。笔者团队经过近 15 a 的产学研攻关,形成了大空间采场远近场坚硬顶板井上下控制理论及技术体系:针对岩层控制研究涉及空间不足,提出了大空间采场概念;基于顶板破断特征及矿压作用规律,定义了远场和近场坚硬顶板;兼顾采空区矸石压缩及覆岩块体的协调运动,建立了大空间采场远场坚硬顶板破断结构力学模型,揭示了远场坚硬顶板破断失稳的强矿压控制机理;基于弹性薄板理论,构建不同切顶工艺、9 种组合边界条件下的近场坚硬顶板初次和周期破断力学模型,揭示了近场坚硬顶板定向造缝采场卸压机理;综合工作面参数、近场矿压作用等基础指标,以及临空开采、双系影响等强化条件,建立了强矿压分级预测评价体系,给出了4 个不同级别矿压显现程度的量化指标及对应的控制技术;研发了坚硬顶板地面水平井体积压裂技术、地面垂直井分级压裂技术,发明了远场坚硬顶板裂缝扩展监测技术,有效解决了远场坚硬顶板强矿压难题;首创了坚硬顶板复合爆破定向精准造缝技术,开发了坚硬顶板液体炸药深孔爆破技术,发明了坚硬顶板链臂锯连续精准切割技术,实现了对近场坚硬顶板垮落形态及破断特征的精准控制;提出了坚硬顶板地面压裂+X 的协同控制技术,实现了对远近场坚硬顶板的多点协同调控。基于以上研究成果,在塔山煤矿 8204 特厚煤层综放面开展了地面水平体积压裂+液体炸药深孔爆破协同控制现场试验,结果表明,在进入压裂爆破协同控制区域后,临空回采巷道顶底板及两帮移近量均小于 388 mm;工作面中部支架最大阻力达到 13 295 kN,小于支架额定工作阻力15 000 kN,工作面及回采巷道强矿压得到了有效控制。

The stope space, after mining an extra-thick coal seam with hard roofs, is large, and its law of mining pressureis complex. The mechanism of strong mine pressure action for this stope is unclear, and there is a lack of multi-point control technology system for different layers of hard roof, so it is necessary to develop a new theory and new technology system for hard roof control in a larger range of stope space. For this reason, the author's team has developed a theory andtechnical system for hard roof control in the large space stopes after nearly 15 years’ industry-university joint research. Inview of limited space covered in the past study of strata control, a concept of large space stope is proposed. Based on theroof break characteristics and the mining pressure laws, the far-field hard roof and near-field hard roof are defined. Considering the gangue compression in goaf and the coordinated movement of overlying rock strata, a mechanical model ofthe break structures for far-filed hard roofs in the large space stope is established, and the control mechanism of the strongmining pressure, due to breakage and instability of the hard roof in the far-field, is revealed. Based on the elastic thin platetheory, the mechanical models of first and periodic breakage for the near-field hard roof with nine boundary conditions fordifferent roof-cutting methods are constructed, and the pressure relief mechanism of directional cutting near-field hard roofis revealed. Combining the basic indexes such as working face parameters, mining pressure effect from the near-field, andthe strengthening conditions such as mining gob-side working faces and double coal seams, a classification prediction andevaluation system of strong mining pressure is established, and the quantitative indexes and corresponding control technologies of four different levels of mining pressure are given. It has developed the ground volume fracturing technology by ahorizontal well on hard roof (GVFTHWHR) and the ground staged fracturing technology by a vertical well on hard roof,and the crack expansion monitoring technology for far-field hard roofs, and effectively solved the problem of strong mining pressure from the far-field hard roof. It has pioneered a technology of directional and precise seam making for hardroof by the composite blasting, developed a technology of deep-hole blasting for hard roofs with liquid explosives(TDHBHRLE), and a technology of continuous and precise hard roof cutting with a chainsaw machine, and realized theprecise control of the collapse shape and breaking characteristics of near-field hard roofs. A technology, the collaborativecontrol of hard roof with ground fracturing +X, is proposed to realize a multi-point collaborative control of hard roof in thefar and near-fields. Based on the above research results, a field test of the collaborative control with the GVFTHWHR andTDHBHRLE is carried out for the hard roof at the 8204 fully mechanized caving working face, an extra-thick coal seamworkface, at the Tashan Coal Mine. The results show that after entering the collaborative control area of fracturing andblasting, the displacement of the roof and floor, and the two sidewalls of the gob-side roadway are less than 388 mm. Themaximum resistance of the support in the middle of the working face reaches 13 295 kN, which is less than 15 000 kN, arated working resistance of hydraulic supports. The strong mining pressure in the working face and roadway has been effectively controlled.

国家自然科学基金资助项目(52204127);重庆市科学家包干制资助项目(CSTC2022YCJH-BGZXM0005);中国博士后基金面上资助项目(2021M700595)

于斌,邰阳,匡铁军,等. 大空间采场远近场坚硬顶板井上下控制理论及技术体系[J]. 煤炭学报,2023,48(5):1875−1893.

YU Bin,TAI Yang,KUANG Tiejun,et al. Theory and technical system of control of far-near field hard roofsfrom ground and underground in a large space stope[J]. Journal of China Coal Society, 2023, 48(5):1875−1893.