深部高瓦斯特软煤层巷道支护技术研究

发布时间：2018-08-06 11:13

【摘要】：梁北矿被国家确认为双突矿井。主采的二1煤层为典型“三软”煤层,倾角为8~15°,厚度一般3~6m,平均4.18m,硬度系数f=0.15~0.25,平均0.18。全层松软,煤层结构简单。当前开采水平-550m,煤巷埋深达610~750m,位于软化临界深度以下,综合支护难度系数超过了1.5~2.0,工程实践表明煤巷支护难度很大。同时,梁北矿煤体松软,透气性差,瓦斯含量高,瓦斯压力大,地应力大,具有较强的突出危险性,且难抽放。在掘进期间,煤巷防突与瓦斯超限等严重影响到煤巷掘进速度,影响到梁北矿采掘接替。本研究主要针对梁北矿深部高瓦斯特软煤层巷道支护难题开展工作。通过对梁北矿-550m水平11采区二1煤层巷道围岩工程地质条件、煤巷变形破坏特征与机理研究,综合考虑瓦斯防突抽放施工和支护稳定性,从提高煤巷掘进速度、确保巷道的稳定性角度,开展了深部高瓦斯特软煤层巷道的支护技术研究。研究中引进了新思想、新材料、新工艺、新技术,取得了如下主要成果:1.提出了高凸钢带-预应力锚网索耦合支护新技术,开发了配套的施工工艺技术,并在11采区煤层试验巷道工程中取得成功,经济效益和社会效益明显。2.解决了薄碎岩层强度测试难题,为后续的工程的分析奠定的坚实的基础。同时,根据岩体结构特性,运用最新版Hoek-Brown强度准则确定工程地质岩组的强度,以此作为数值计算分析中参数值确定的重要参考依据,提高了数值分析计算结果的可信性。3.划分了工程地质岩组,确定了11采区煤层巷道的变形力学机制,找出了原支护护条件下煤层巷道变形破坏的主要原因,制定了正确的支护对策,应用高凸钢带-预应力锚网索耦合支护新技术,成功地解决了11采区实体煤巷的稳定性控制难题。4.基于低渗透储层改造的有效途径是采用卸压技术的基本思想,从巷道支护稳定性和高效抽放协同作用的角度,对原方案进行了调整,调整后的方案使实体煤巷掘进速度由原来的45m/月提高到70m/月以上,解决了梁北矿11采区煤巷瓦斯防突与超标问题,实现了煤巷的快速掘进。5.把“三软”煤巷瓦斯治理与巷道支护技术有机结合起来,在巷道掘进瓦斯突的过程中,不破坏巷边煤层,在此基础上,对煤帮采取锚网支护,提高煤帮稳定性,弱化了底鼓效应。综合技术的采用,有效地解决了梁北矿高瓦斯软煤层巷道的快速掘进问题,缓解了采掘接替的压力。
[Abstract]:Liangbei mine was recognized as a double-burst mine by the state. The second coal seam of main mining is a typical "three soft" coal seam with a dip angle of 815 掳, a thickness of 3 ~ 6 m, an average of 4.18 m, and a hardness coefficient of 0.15 ~ 0.25, with an average of 0.18 m. The whole layer is soft and the coal seam structure is simple. At present, the mining level is -550 m, the depth of coal roadway is 610 ~ 750m, which is below the softening critical depth, and the comprehensive support difficulty coefficient is more than 1.5 ~ 2.0. The engineering practice shows that the coal roadway support is very difficult. At the same time, the coal body of Liangbei Coal Mine is soft, gas permeability is poor, gas content is high, gas pressure is large, ground stress is large, it has strong outburst danger, and it is difficult to drain. During the tunneling period, the outburst prevention and gas outage of coal roadway seriously affect the tunneling speed of coal roadway and the mining replacement of Liangbei Coal Mine. This research mainly aims at the difficult problem of roadway support in deep high gas soft coal seam in Liangbei Coal Mine. Through studying the engineering geological conditions of surrounding rock, deformation and failure characteristics and mechanism of coal roadway in No. 2 coal seam of -550 m level 11 mining area in Liangbei Mine, considering comprehensively the construction of gas outburst drainage and the stability of support, the paper improves the tunneling speed of coal roadway. In order to ensure the stability of roadway, the supporting technology of deep high gas soft seam roadway is studied. New ideas, new materials, new techniques and new technologies have been introduced into the research, and the following main achievements have been achieved: 1. A new technology of coupling support of high convex steel strip with prestressed anchor mesh and cable is put forward, and the matching construction technology is developed. The construction technology is successful in the coal seam test roadway project of 11 mining area, and the economic and social benefits are obvious. 2. It solves the problem of strength testing of thin rock bed and lays a solid foundation for subsequent engineering analysis. At the same time, according to the structural characteristics of rock mass, the strength of engineering geological rock group is determined by the latest version of Hoek-Brown strength criterion, which can be used as an important reference for the determination of parameter value in numerical calculation and analysis, and improves the credibility of the numerical analysis results. The engineering geological rock group is divided, the deformation mechanics mechanism of coal seam roadway in 11 mining area is determined, the main reason of coal seam roadway deformation and failure under the condition of original support and protection is found out, and the correct supporting countermeasure is worked out. By using the new technology of coupling support of high convex steel strip with prestressed anchor mesh and cable, the problem of stability control of coal roadway in 11 mining area has been solved successfully. Based on the basic idea of pressure relief technology, this paper adjusts the original scheme from the angle of roadway support stability and high efficiency drainage synergy, based on the effective way of low permeability reservoir reconstruction. The adjusted scheme increases the driving speed of solid coal roadway from the original 45m/ month to above 70m/ month, solves the problem of gas outburst prevention and over-standard in coal roadway in 11 mining area of Liangbei Mine, and realizes the rapid tunneling of coal roadway .5. Combining the gas treatment of "three soft" coal roadways with the roadway support technology organically, the coal seam beside the roadway is not destroyed in the process of roadway driving gas outburst. On this basis, the bolting net support is adopted to improve the stability of the coal side. The effect of bottom drum is weakened. The adoption of comprehensive technology has effectively solved the problem of rapid excavation of high gas soft coal seam roadway in Liangbei Coal Mine and alleviated the pressure of mining replacement.
【学位授予单位】：河南理工大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：TD353

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