冲沟发育地貌浅埋煤层开采覆岩运动及裂隙演化规律研究

发布时间：2018-05-01 23:01

本文选题：冲沟发育地貌 + 浅埋煤层　；参考：《中国矿业大学》2016年硕士论文

【摘要】：我国西北矿区普遍赋存浅埋煤层且冲沟地貌发育,导致冲沟发育地貌煤层开采与常规浅埋相互影响更为敏感和强烈,致使工作面开采矿压显现规律、地表裂隙特别是地表冲沟坡体及沟底裂隙呈现出新特征,冲沟水体通过覆岩裂隙迁移进入工作面引起水患等对矿井安全高效生产产生极为不利影响。本文以色连一号矿淖沟为冲沟研究对象,针对该矿冲沟发育地貌浅埋煤层开采条件,综合运用现场调研、理论分析、数值模拟、物理模拟、现场实测和瞬变电磁探测等研究方法,对冲沟发育地貌浅埋煤层开采覆岩运动及裂隙演化规律进行了系统的研究,主要研究成果如下:(1)建立数值模拟和物理模拟模型分析过冲沟期间覆岩运动规律,覆岩运动未发育至冲沟其运动特征与常规浅埋基本相同,覆岩运动发育至冲沟后冲沟对覆岩运动影响较大,基本顶周期破断步距、强度,冲沟坡体运动特征,基本顶及冲沟下岩层垂直应力、位移量变化、顶板冒落与支架形态均出现明显不同。(2)通过现场实测发现工作面过冲沟期间矿压显现规律较常规浅埋具有显著特征:(1)支架最大工作阻力增大;(2)来压动载系数增大;(3)周期来压步距在冲沟各区域明显不同。冲沟向沟区域、沟底、背沟区域具有如下特征:(1)周期来压步距背沟开采小于向沟开采;(2)支架工作阻力背沟开采大于向沟开采,大于沟底开采;(3)动载系数背沟开采大于向沟开采,大于沟底开采。(3)分析了工作面过冲沟期间覆岩裂隙演化规律,发现覆岩裂隙发育至冲沟,向沟坡体和背沟坡体产生向冲沟方向倒转趋势。现场对向沟坡体裂缝进行实测,发现其表现形态主要为波浪型、近似直线型、台阶下沉、地堑等形式,对此提出降高开采安全通过冲沟的方法。(4)采用PROTEM CM瞬变电磁探测工作面过冲沟煤层开采覆岩裂隙发育特征,综合分析视点阻率随时间变化规律、冲沟地表裂缝发育与含水层水位变化规律,表明工作面覆岩导水裂隙导通冲沟,现场验证了数值模拟与物理模拟结果。(5)结合冲沟发育地貌浅埋煤层过冲沟开采覆岩运动和裂隙演化规律分析研究,针对该地夏季雨水多,积水多,冬季雨水少,积水少且易结冰的特征,提出了选择非汛期过冲沟、降高开采、冲沟下快速推进等防控技术,实现了冲沟发育地貌浅埋煤层安全高效开采。
[Abstract]:Shallow coal seam and gully geomorphology are common in the mining area of northwest China, which leads to the more sensitive and strong interaction between the mining of geomorphic coal seam and the normal shallow buried coal seam, which results in the regularity of mining pressure in mining face. The surface fissures, especially the surface gully slope body and the gully bottom fissure show new characteristics, and the movement of the gully water body into the face through the overlying rock fissure causes the flood hazard to the mine safety and efficiency production. Aiming at the mining conditions of shallow buried coal seam developed by geomorphology in the trench of Xielian No.1 Mine, this paper makes comprehensive use of field investigation, theoretical analysis, numerical simulation and physical simulation. Field measurement and transient electromagnetic detection are used to systematically study the movement of overburden and the evolution of cracks in shallow coal seams developed in the gully. The main research results are as follows: (1) numerical and physical simulation models are established to analyze the overburden movement during the gully period. The overlying movement is not developed to the gully and its movement characteristics are basically the same as those of the conventional shallow burying. The overburden movement develops to the gully and the gully has a great influence on the overburden movement. The breakage interval, the strength, the movement characteristics of the slope body, the vertical stress and the displacement change of the basic roof and subgully rock layer, the basic top cycle breaking step, the strength, the movement characteristic of the slope of the gully, Roof caving and support form are obviously different. 2) through the field measurement, it is found that the characteristics of mine pressure behavior during the working face over gully are significant characteristics compared with the normal shallow burying.) the maximum working resistance of the support increases and the pressure load coefficient increases. The interval of pressure step is obviously different in every region of the gully. The trench area, the furrow bottom, the back trench area has the following characteristics: 1) the period of back trench mining is less than that of the trench mining, the working resistance back ditch mining is greater than the trench mining, the trench mining is larger than the trench mining, the moving load coefficient back ditch mining is larger than the trench mining. It is found that the overlying rock fissure develops to the gully, the trench slope body and the back trench slope body produce the reverse trend of the gully direction. On the spot, the cracks in the trench slope body are measured, and it is found that the main forms are wave type, approximate straight line type, step sinking, graben and so on. In this paper, the authors put forward the method of safe passing through the gully in reducing the height mining. 4) adopt PROTEM CM transient electromagnetic detection to detect the development characteristics of overburden cracks in the coal seams in the working face, and comprehensively analyze the law of the resistance rate of view point changing with time. The development of surface cracks in gullies and the variation of aquifer water level indicate that the overburden rock and water diversion fissures lead to the gullies. Field verification of numerical and physical simulation results. 5) combined with the analysis and study of overlying rock movement and fracture evolution of shallow buried coal seams developed by gully, aiming at the large number of Rain Water and water in summer, and the small amount of Rain Water in winter. Based on the characteristics of low water accumulation and easy ice formation, this paper puts forward some prevention and control techniques, such as selecting non-flood season over gully, reducing high mining height and rapidly advancing under gully, so as to realize safe and efficient mining of shallow buried coal seam developed by gully.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TD325

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