摘要
寻找巨厚煤层上覆岩层裂隙带位置,合理布置高位钻孔的终孔位置,是提高巨厚煤层瓦斯抽采效率的关键。采用相似模拟,对水帘洞煤矿3801巨厚煤层综放工作面上覆岩层裂隙演化规律进行了试验研究。通过试验将上覆岩层裂隙演化分为6个区———顶板运动不明显区、微弱区、明显区、剧烈区、缓和区和稳定区;得出上覆岩层冒落带上限高度为45-55 m,裂隙带上限高度为93.0-100.7m。上覆岩层中出现垂直应力集中区和卸压区,覆岩离层主要出现在应力卸压区,在应力集中区或煤柱外侧不可能出现离层。根据试验结论,在水帘洞煤矿3801工作面布置了高位钻孔,现场应用结果表明：高位瓦斯抽采钻孔布置在距煤层顶板50m左右的范围内,其钻孔抽采平均瓦斯体积分数达到42%,6个钻孔平均抽放纯量为5.9m3/min。
This paper is to reportthe results of our experimental study on a renovated approach to extracting the high-level borehole draining gas in the case of fully mechanized extro-thick coal seam, which is regarded as the key to improving the extraction efficiency of such a case for this purpose, we have done field tests, through which we have found that it is necessary to divide the overlying strata crack evolution into six areas： the insignificant area of the roof movement, the weak roof movement area, the noticeable movement area, the badly affected area, the slightly affected area and the stable area. We have found that the ceiling of the exploiting area is about 45-55 m highwhereas that of the fissure area is 93.0-100.7 m high with the overburdened strata. Through testing and measurement, we have found that the vertical displacement is different on the coal seam roof with the roof subsidence decreasing upward along the seam floor. It has also been found that there has occurred vertical stress concentration and pressure relief in the overburdened strata, whereas the stress relief mainly appears in the separated strata. However, it would be unlikely for abscission to appear in the stress-concentrated area or outside of the coal pillar. It is for this reason that we recommend to use high-level borehole to control the gas draining in the similar conditions, and, what is more, high-level boreholes, that is, above 50 m above the seam roof, should be arranged in the place between the lower range of the caving zone and the upper range of the fractured zone. Thus, it can be concluded that high level boreholes should be laid in No. 3801 working face of Shuiliandong coal mine in a range of about 50 m from the coal seam roof, where the average gas extraction concentration should reach 42% and the average pure extraction eff-i ciency of the six boreholes should be getting to 5.9 m3/min. The above study results prove to be of great instructive significance to gas management of the working areas in similar circumstances.
出处
《安全与环境学报》
CAS
CSCD
北大核心
2013年第3期218-222,共5页
Journal of Safety and Environment
基金
国家自然科学基金项目(51004003,50974004)
安徽省教育厅自然科学基金重点项目(KJ2010A091)
关键词
安全工程
巨厚煤层
上覆岩层
裂隙演化
相似模拟
高位钻孔
safety engineering
extremelythick coal seam
overlying strata
cracks evolution
similar simulation
high level borehole
