综放面顶层巷小煤柱外错底层回风巷布置及其围岩稳定性研究
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摘要
瓦斯灾害已成为煤矿安全生产的重要隐患,特别是厚及特厚煤层,随着综放工作面长度和底层采高的加大,以及工作面产量的急剧增加,工作面上隅角瓦斯的积聚,势必造成通风和瓦斯管理上的困难,严重地制约着工作面的安全生产和生产进度。设计合理的供风量和选取更合适瓦斯巷道布置系统,是解决放顶煤工作面瓦斯、煤尘积聚最为有效方式之一。
本文提出了一种全新的综放工作面通风系统:顶层瓦斯巷小煤柱外错底层回风顺槽布置,具体是一种放顶煤工作面顶板排瓦斯巷位置的改进。从根本上解决放顶煤工作面上段、上隅角和采空区的瓦斯与煤尘积聚,特别是上隅角上部空间瓦斯与煤尘的积聚提供了安全、高效的通风系统,并为实现小煤柱放顶煤开采,提高煤炭回收率创造了良好的力学环境,增加了端头顶煤的回收。同时,顶层巷存在,可有效地吸收煤体中高应力作用产生的大量变形,释放煤体中积聚的弹性能,可有效地促使采动引起的应力再次重新分布,改善区段煤柱内高应力环境,使被保护巷道处于应力降低区内。
运用正交实验方案定量和定性地研究了综放面采用顶层瓦斯巷外错式布置下,煤层厚度、赋存深度、煤体强度及顶板强度对回风顺槽、顶层巷和相邻工作面运输顺槽围岩稳定性影响的相关规律,对影响程度进行了主次排序,确定出了合理的小煤柱尺寸范围。
在此基础上,综合运用以巷道围岩稳定性分类为基础的工程类比设计法、锚杆支护专家系统设计法、基于地质力学条件的三维数值模拟设计法,总结出顶层巷外错式布置下巷道合理的支护方案。最后,成功地将上述结论运用于厚及特厚煤层综放工作面,达到了预期的效果。
Gas disaster has become a major hazards in coal mine’s safety production, especially thick and extremely thick coal seam. While work face lengths, mining height sends up, production increases speedily and gas accumulates full of upside corner, it will inevitably result in ventilation and gas management difficultily, which seriously restricts the safe production and production schedule of mining face. How to disign well the air volume and to selecte a more suitable gas roadway layout system, which is one of the most effective way to solve gas and coal dust accumulation.
This paper proposes a new working face ventilation system: top gas tunnel small pillar outside the bottom return air laneway layout, in other words, which is gas tunnel location evolution. It is a fundamental solution to gas and dust accumulation full of the work surface caving section and upper corner of mined area, which provide a safe, efficient ventilation system, achieve small coal pillar arrangement in the top-coal caving, create a good mechanical environment to improve the recovery rate of coal and increased the recovery of the end coal of work face. Meanwhile, the top tunnel existing, can effectively absorb the coal’s deformation produced in a large number of high-stress, release of elastic energy accumulated in the coal , promote effectively the stress caused by mining to distribute again, improve the high-stress environment in pillars, and make the tunnel protected in the region of low stress.
The orthogonal experimental program obtained related laws of coal thickness, buride depth, coal strength and roof strength how to influence the stability of surrounding rock, arrange the inportant role in order and determine reasonable size of small pillar, based on the top tunnel outside bottom return air laneway arrangement.
On these basis, by comprehensively using engineering analogy based on the classification of surrounding rock stability of roadway, design method of expert system, 3-dimention numerical simulation based on the geomechanics condition, the paper summed up reasonable tunnel support scheme while using top tunnel outside bottom return air laneway layout. Finally, these conclusions are applied successfully in thick and extra-thick seam and achieve the desired results.
本文提出了一种全新的综放工作面通风系统:顶层瓦斯巷小煤柱外错底层回风顺槽布置,具体是一种放顶煤工作面顶板排瓦斯巷位置的改进。从根本上解决放顶煤工作面上段、上隅角和采空区的瓦斯与煤尘积聚,特别是上隅角上部空间瓦斯与煤尘的积聚提供了安全、高效的通风系统,并为实现小煤柱放顶煤开采,提高煤炭回收率创造了良好的力学环境,增加了端头顶煤的回收。同时,顶层巷存在,可有效地吸收煤体中高应力作用产生的大量变形,释放煤体中积聚的弹性能,可有效地促使采动引起的应力再次重新分布,改善区段煤柱内高应力环境,使被保护巷道处于应力降低区内。
运用正交实验方案定量和定性地研究了综放面采用顶层瓦斯巷外错式布置下,煤层厚度、赋存深度、煤体强度及顶板强度对回风顺槽、顶层巷和相邻工作面运输顺槽围岩稳定性影响的相关规律,对影响程度进行了主次排序,确定出了合理的小煤柱尺寸范围。
在此基础上,综合运用以巷道围岩稳定性分类为基础的工程类比设计法、锚杆支护专家系统设计法、基于地质力学条件的三维数值模拟设计法,总结出顶层巷外错式布置下巷道合理的支护方案。最后,成功地将上述结论运用于厚及特厚煤层综放工作面,达到了预期的效果。
Gas disaster has become a major hazards in coal mine’s safety production, especially thick and extremely thick coal seam. While work face lengths, mining height sends up, production increases speedily and gas accumulates full of upside corner, it will inevitably result in ventilation and gas management difficultily, which seriously restricts the safe production and production schedule of mining face. How to disign well the air volume and to selecte a more suitable gas roadway layout system, which is one of the most effective way to solve gas and coal dust accumulation.
This paper proposes a new working face ventilation system: top gas tunnel small pillar outside the bottom return air laneway layout, in other words, which is gas tunnel location evolution. It is a fundamental solution to gas and dust accumulation full of the work surface caving section and upper corner of mined area, which provide a safe, efficient ventilation system, achieve small coal pillar arrangement in the top-coal caving, create a good mechanical environment to improve the recovery rate of coal and increased the recovery of the end coal of work face. Meanwhile, the top tunnel existing, can effectively absorb the coal’s deformation produced in a large number of high-stress, release of elastic energy accumulated in the coal , promote effectively the stress caused by mining to distribute again, improve the high-stress environment in pillars, and make the tunnel protected in the region of low stress.
The orthogonal experimental program obtained related laws of coal thickness, buride depth, coal strength and roof strength how to influence the stability of surrounding rock, arrange the inportant role in order and determine reasonable size of small pillar, based on the top tunnel outside bottom return air laneway arrangement.
On these basis, by comprehensively using engineering analogy based on the classification of surrounding rock stability of roadway, design method of expert system, 3-dimention numerical simulation based on the geomechanics condition, the paper summed up reasonable tunnel support scheme while using top tunnel outside bottom return air laneway layout. Finally, these conclusions are applied successfully in thick and extra-thick seam and achieve the desired results.
引文
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