【摘要】：針對(duì)西部礦區(qū)淺埋深、薄基巖和厚煤層的賦存特點(diǎn)和煤層開(kāi)采過(guò)程中覆巖斷裂裂縫貫通地表并導(dǎo)致地表漏風(fēng),并由此引起工作面通風(fēng)紊亂、采空區(qū)CO濃度超限、存在遺煤自燃隱患等影響安全生產(chǎn)的問(wèn)題。本文以?xún)?nèi)蒙古串草圪旦煤礦地質(zhì)賦存及生產(chǎn)技術(shù)條件為背景,從覆巖結(jié)構(gòu)運(yùn)動(dòng)與空氣流動(dòng)學(xué)的角度出發(fā),綜合采用現(xiàn)場(chǎng)實(shí)測(cè)、相似材料模擬、數(shù)值計(jì)算、理論分析、現(xiàn)場(chǎng)工業(yè)性試驗(yàn)等研究方法,對(duì)淺埋厚煤層高強(qiáng)度開(kāi)采條件下覆巖失穩(wěn)運(yùn)動(dòng)特征及斷裂裂縫的動(dòng)態(tài)分布與發(fā)展變化規(guī)律、覆巖導(dǎo)氣裂縫的產(chǎn)生機(jī)理及其時(shí)空演化規(guī)律、導(dǎo)氣裂縫影響下采空區(qū)流場(chǎng)及工作面漏風(fēng)特征等進(jìn)行了系統(tǒng)深入地研究,提出了基于覆巖導(dǎo)氣裂縫控制的淺埋厚煤層開(kāi)采安全保障技術(shù)。研究成果對(duì)于西部礦區(qū)淺埋厚煤層高強(qiáng)度開(kāi)采巖層控制和安全生產(chǎn)具有重要的理論價(jià)值和現(xiàn)實(shí)意義�；诖蒇俚┟旱V淺埋厚煤層開(kāi)采工程地質(zhì)條件,實(shí)測(cè)得出了不同埋深、覆蓋層厚度條件下工作面地表采動(dòng)裂縫時(shí)空分布規(guī)律、動(dòng)態(tài)發(fā)育特征及其主控因素,以及地表漏風(fēng)強(qiáng)度、采空區(qū)氣體濃度分布規(guī)律及其相關(guān)關(guān)系。分析歸類(lèi)了地表采動(dòng)裂縫的類(lèi)型及其對(duì)工作面安全生產(chǎn)的影響。建立了覆巖承載關(guān)鍵層深梁結(jié)構(gòu)力學(xué)模型,得出了深梁結(jié)構(gòu)承載關(guān)鍵層初次破斷和周期性破斷的破斷特征、失穩(wěn)運(yùn)動(dòng)形式及其影響因素,以及覆巖貫通型地裂縫的形成機(jī)理。分析了承載關(guān)鍵層層位、基巖厚度、松散覆蓋層厚度、工作面推進(jìn)速度以及地表地形等對(duì)淺埋厚煤層開(kāi)采覆巖破斷失穩(wěn)及斷裂裂縫時(shí)空演化規(guī)律的影響,得出了覆巖斷裂裂縫的動(dòng)態(tài)時(shí)空演化特征、類(lèi)型和分布范圍。建立了淺埋厚煤層開(kāi)采覆巖導(dǎo)氣裂縫空氣流動(dòng)力學(xué)分析模型,分析了覆巖導(dǎo)氣裂縫的導(dǎo)氣機(jī)理及導(dǎo)氣特征,確定了覆巖導(dǎo)氣裂縫的分布特征、導(dǎo)氣條件,得出了基于覆巖導(dǎo)氣裂縫等效縫寬的淺埋厚煤層開(kāi)采覆巖導(dǎo)氣裂縫漏風(fēng)流量q￠及平均漏風(fēng)流速m￠的計(jì)算公式。通過(guò)現(xiàn)場(chǎng)實(shí)測(cè)分析和計(jì)算流體力學(xué)分析相結(jié)合,得出了覆巖導(dǎo)氣裂縫在工作面推進(jìn)方向上的時(shí)空分布規(guī)律,建立了覆巖導(dǎo)氣裂縫的演化模型,為導(dǎo)氣裂縫影響下采空區(qū)內(nèi)漏風(fēng)流場(chǎng)時(shí)空分布規(guī)律的分析奠定了理論基礎(chǔ)。建立了基于導(dǎo)氣裂縫控制的工作面安全生產(chǎn)保障條件,提出了保障工作面安全生產(chǎn)的技術(shù)途徑。包括減緩覆巖導(dǎo)氣裂縫內(nèi)漏風(fēng)流速的填平封堵技術(shù),防止采空區(qū)覆巖導(dǎo)氣裂縫漏風(fēng)的工作面增壓通風(fēng)技術(shù),預(yù)防采空區(qū)遺煤自燃的淺埋厚煤層開(kāi)采采空區(qū)注漿、注氮技術(shù)及保證工作面一定推進(jìn)速度等。
[Abstract]:Aiming at the characteristics of shallow buried depth, thin bedrock and thick coal seam in the west mining area, and the overlying rock fracture through the surface during the coal seam mining, which leads to the surface air leakage, and thus causes the ventilation disorder of the working face, the CO concentration in the goaf exceeds the limit. There are some problems such as hidden danger of coal spontaneous combustion affecting production safety. Based on the geological occurrence and production conditions of Cangcao Gedan Coal Mine in Inner Mongolia, from the point of view of overburden structure movement and air flow, the field measurement, simulation of similar materials, numerical calculation and theoretical analysis are adopted in this paper. Based on the field industrial tests, the characteristics of overburden instability movement, the dynamic distribution and development of fracture fractures, the generation mechanism and space-time evolution law of overburden gas fractures under the condition of high strength mining in shallow buried thick coal seam are studied. Under the influence of gas fissures, the flow field in goaf and the characteristics of air leakage in working face are studied systematically and deeply, and the mining safety guarantee technology of shallow buried thick coal seam based on gas crack control of overburden rock is put forward. The research results have important theoretical value and practical significance for the control and safe production of strata in high strength mining of shallow thick coal seam in western mining area. Based on the mining engineering geological conditions of shallow thick coal seam in Xuancao Gedan coal mine, the temporal and spatial distribution law, dynamic development characteristics and main controlling factors of mining cracks in working face under different buried depth and overburden thickness are obtained. And the air leakage intensity, gas concentration distribution in goaf and its correlation. This paper analyzes and classifies the types of surface mining cracks and their influence on working face safety. The mechanical model of the deep beam structure of the key strata bearing overburden is established. The fracture characteristics of the first and periodic breaking of the critical layer bearing the deep beam structure, the form of instability and its influencing factors, as well as the formation mechanism of the ground fracture of the overburden through type are obtained. This paper analyzes the influence of bearing key layers, bedrock thickness, loose overburden thickness, working face advancing speed and surface topography on the time-space evolution law of overburden rock fracture instability and fracture in shallow buried thick coal seam mining. The dynamic temporal and spatial evolution characteristics, types and distribution range of overburden fracture fractures are obtained. The air flow mechanics analysis model of overburden gas fracture in shallow buried thick coal seam is established. The gas conduction mechanism and gas conduction characteristics of overburden gas fracture are analyzed, and the distribution characteristics and gas conduction condition of gas fracture in overburden rock are determined. The formula of air leakage flow Q and average air leakage velocity m of overburden gas fracture in shallow buried thick coal seam based on equivalent fracture width of overburden gas conductivity fracture is obtained. Through the combination of field measurement analysis and computational fluid dynamics analysis, the space-time distribution law of overburden gas crack in the working face is obtained, and the evolution model of overburden gas crack is established. It lays a theoretical foundation for the analysis of the spatial and temporal distribution of air leakage field in goaf under the influence of gas conduction cracks. The working face safety production guarantee condition based on the gas guide crack control is established, and the technical way to ensure the working face safety production is put forward. It includes filling and plugging technology to slow air leakage velocity in overburden gas crack, working face pressurized ventilation technology to prevent air leakage from gas crack in overburden rock in goaf, and grouting in mining goaf in shallow thick coal seam, which can prevent spontaneous combustion of coal in goaf. Nitrogen injection technology and ensure the working face certain speed of advance, etc.
【學(xué)位授予單位】：中國(guó)礦業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類(lèi)號(hào)】：TD325;TD728
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本文編號(hào)：2212438