静态破碎法在高瓦斯矿井巷道端头顶板控制垮落中的应用研究

发布时间：2018-06-16 02:09

本文选题：高瓦斯矿井 + 静态破碎　；参考：《太原理工大学》2014年硕士论文

【摘要】：顶板坚硬程度、支护方式与强度、上覆岩层移动规律等因素影响着回采工作面端头弧形三角区顶板的悬顶距离,过大的悬顶距离会导致该区域瓦斯浓度超限,同时引起其它方面的问题,特别是高瓦斯矿井,弧形三角区悬顶问题已经成为亟需解决的难点问题。本文探讨了处理悬顶问题的两种主要方法：预裂爆破和水压致裂,对比这两种技术方法的优缺点及适用条件；结合阳煤集团三矿回采工作面端头弧形三角区顶板的悬顶情况,得出预裂爆破和水压致裂不适合高瓦斯矿井处理悬顶的结论。本文引入“静态破碎技术”处理高瓦斯矿井工作面端头的悬顶的构想,实现对弧形三角区顶板安全、高效、环保的控制垮落过程。通过理论分析+实验研究+现场工业性试验相结合的方法,分析了回采巷道端头弧形三角区形成条件及对周围煤柱的影响,并计算了弧形三角区悬顶的最大距离,通过对K8113工作面的钻孔窥视,了解了工作面上覆岩层移动情况；研究了静态破碎技术破岩机理,完成了静态破碎剂的物理化学参数测定,包括：密度、容重、膨胀压力、与水混合密度、反应放热量,以及膨胀压力与孔径关系、最佳水灰比等重要参数的测定；实验室内得出了静态破碎过程中岩体内裂纹产生形式；利用声发射定位技术,监测了裂纹扩展的全过程,得出了“裂纹扩展先从孔中下部孔壁开始”、“先发生裂纹先于后发生裂纹扩展”、“裂纹扩展速度先快后慢”、“垂直层理方向裂纹拓展速度大于平行层理方向裂纹拓展速度”等重要结论;依据弹性力学与裂纹力学理论,分析静态破碎剂破岩过程中钻孔周围裂纹起裂、扩展及止裂过程,建立了静态破碎裂纹扩展模型,结果显示：静态破碎剂的作用力及裂纹扩展长度的关系,及裂纹扩展半径；为了进一步确定破碎剂作用的机理以及合适的钻孔布置参数,通过大型有限元软件ANSYS4.0对煤体胀裂过程的效果进行模拟,得出钻孔理想间排距应小于0.8m；设计了合理的钻孔参数,然后在K8113工作面回风巷端头实施了静态破碎人工强制放顶技术,获得了理想的试验效果。 K8113工作面退锚、剪网都达到要求后,没有经过悬顶处理的落山悬顶长度一般在20m以上。本研究工业性试验进行数小时后,当机头向前推进3.2m后,落山巷道顶煤开始逐步冒落,老顶石灰岩也逐步开始垮落；又推进约9.6m后,试验区域已完全垮落。未处理悬顶时和注浆处理相比,悬顶距离减少了7.2m。本研究的实施,避免了高瓦斯矿井回采巷道端头悬顶带来的通风死角和采空区漏风等安全问题,同时降低了切眼处和采空区两侧煤柱的支承压力,验证了静态破碎技术适用于高瓦斯矿井人工强制放顶的结论。该研究成果在阳煤集团具有重要的推广价值,同时为其他矿区处理类似问题提供了实际参考,是很有意义的。
[Abstract]:The roof hardness, support mode and strength, the law of overlying strata movement and other factors affect the roof suspension distance of the arc triangle area of the end of the mining face, and the excessive hanging roof distance will cause the gas concentration in this area to exceed the limit. At the same time, it has become a difficult problem to solve the problems in other aspects, especially in high gas mine, arc triangle area suspended roof problem. This paper discusses two main methods to deal with the problem of suspended roof: presplit blasting and hydraulic fracturing, compares the advantages and disadvantages of these two technical methods and their applicable conditions, and combines with the suspended roof of the end arc triangle area of the coal mining face of Yangyang Coal Group Group No. 3 Coal Mine. It is concluded that presplit blasting and hydraulic fracturing are not suitable for roof suspension treatment in high gas mines. In this paper, the concept of "static crushing technology" is introduced to deal with the suspended roof at the end of high gas mine face, which can control the collapse process of arc triangle roof safely, efficiently and environmentally. By means of theoretical analysis and experiment, the formation conditions of arc triangle at the end of mining roadway and its influence on the surrounding coal pillar are analyzed, and the maximum distance of suspended roof of arc triangle area is calculated. By peeping through the boreholes of K8113 working face, the movement of overlying strata is understood, the mechanism of rock breaking by static crushing technology is studied, and the physical and chemical parameters of static crushing agent are determined, including density, bulk density, expansion pressure, etc. Measurement of important parameters such as mixing density with water, heat release from reaction, relationship between expansion pressure and pore size, optimum water-cement ratio and other important parameters; formation of cracks in rock body during static crushing in laboratory; use of acoustic emission localization technology, The whole process of crack growth is monitored, and it is concluded that "crack propagation begins with the hole wall of the middle and lower part of the hole", "the crack first occurs before the crack growth", and "the crack growth rate is first fast and then slow". According to the theory of elastic mechanics and crack mechanics, the crack initiation, propagation and crack stopping process around the borehole during the rock breaking process of static fracturing agent are analyzed, such as "the crack expansion speed in the vertical bedding direction is faster than the crack expansion velocity in the parallel bedding direction", and so on. The static crack propagation model is established. The results show that the relationship between the force of static crushing agent and the length of crack propagation, and the radius of crack propagation, in order to determine the mechanism of the effect of the agent and the appropriate drilling parameters, By simulating the effect of expanding and cracking process of coal body by ANSYS 4.0, it is concluded that the ideal spacing between boreholes should be less than 0.8 m.The reasonable drilling parameters are designed. Then the static crushing artificial forced caving technology is implemented at the end of return air roadway of K8113 face, and the ideal test result is obtained. The length of the downhill suspended roof is generally more than 20m. After a few hours of industrial test, the roof coal of the downhill roadway began to fall gradually, and the limestone of the main roof began to collapse gradually after the machine head was pushed forward 3.2 m, and the test area had completely collapsed after advancing about 9.6 m. Compared with the grouting treatment, the suspended roof distance decreases by 7.2 mm. when the suspended roof is untreated. The implementation of this study avoids the safety problems of ventilation dead angle and air leakage in goaf caused by the hanging roof of the end of mining roadway in high gas mine, and at the same time reduces the supporting pressure of coal pillar at the cutting hole and both sides of the goaf. The conclusion that static crushing technology is suitable for artificial forced roof caving in high gas mine is verified. The results of this study are of great value to be popularized in Yang Coal Group, and also provide practical reference for other mining areas to deal with similar problems, which is of great significance.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TD712;TD327.2

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