西部煤炭集约化开采损伤传导机理与源头减损关键技术
Damage conduction mechanism and key technologies of damage reduction insources for intensive coal mining in Western China
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摘要: 科学认识开采损伤传导机理是井下安全生产、含水层保护及地表附属物减损理论发展及减损关键技术提出与实践的核心问题,研究西部煤炭集约化开采损伤传导机理与源头减损关键技术,对协调我国能源需求保障和矿区生态保护具有重要意义。通过分析集约化开采特征和现有减损技术特点,基于神东矿区集约化开采现场实测与模拟,研究了西部集约化开采损伤规律,揭示覆岩损伤传导机理。研究表明,神东矿区集约化开采具有矿压显现强烈、覆岩损伤严重、移动周期短、地表变形剧烈、地表裂缝发育等规律;首次发现神东上湾煤矿“基本顶破断-关键层断裂-地表主裂缝”呈“331”周期性传导规律,得出西部煤炭集约化开采覆岩及地表损伤具有周期性对应传导关系。揭示了覆岩损伤逐层上传、分区耗散的机理;提出了采动损伤能及极限损伤能临界值计算方法;建立了覆岩“三带”不同分区损伤系数与开采空间关系的损伤耗散模型,得出源头减损是控制开采损伤的主要途径。兼顾集约化开采特征,分别围绕覆岩损伤控制、地表变形控制等不同目的,提出了开采工艺参数优化、覆岩承载结构稳定性维持和变形调控减损的集约化开采源头减损关键技术,并给出工作面采高、面长及推进速度的合理区间。运用该方法对上湾煤矿12402工作面进行了开采优化,并用数值计算方法对比分析了优化前后覆岩损伤程度和控制效果。Abstract: Scientific understanding of mining damage conduction mechanism is the core issue for safe production in coal mines,aquifer protection and the development of theory on surface appendages damage reduction and key technologies for damage reduction.It is of significance to study the damage conduction mechanism of coal intensive mining in Western China and the key technologies of reducing damage from sources,which is also of significance to coordinate energy demand and ecological protection of mining areas in China.Therefore,considering the characteristics of intensive mining and the characteristics of existing damage reduction technologies,based on the field measurement and simulation of intensive mining in Shendong mining area,the damage law is analyzed,and the damage conduction mechanism of overburden is revealed.The results show that there are some laws of the intensive mining in Shendong mining area such as strong ground pressure behavior,serious overburden damage,severe surface deformation,short movement period,and high development degree of surface cracks.For the first time,it is found that the “basic roof fracture - key stratum fracture-surface main crack” presents a “331” periodic conduction law,and it is concluded that there is a periodic corresponding conduction law between the surface damage and overburden damage of intensive coal mining in western China.This paper reveals the mechanism of overlying rock damage ascending layer by layer and dissipating in different regions,and puts forward the calculation method of mining damage energy and limit damage energy critical value,and establishes the damage JP2dissipation model of different division damage coefficient of overburden “three zones” and mining space,and concludes that reducing damages from sources is the fundamental and effective way to control mining damage.Taking into account the characteristics of intensive mining,focusing on the different purposes of overburden damage control and surface deformation control,the paper puts forward some key technologies of damage reduction from intensive mining sources,including the optimization of mining process parameters,the maintenance of stability of bearing structure of overburden and deformation control to reduce damage,and gives reasonable ranges of mining height,length and advancing speed of working face.The mining optimization of the 12402 working face in the Shangwan Coal Mine is carried out by using this method,and the damage degree and control effect of overburden before and after optimization are compared and analyzed using numerical calculation method.