节点文献
新集煤矿远程下保护层开采卸压范围及效果研究
Study on the Pressure-unloading Area and Effect for Far Distance Lower-protection Mining of Xing Ji Coal Mine
【作者】 胡恩宝；
【导师】 戴广龙；
【作者基本信息】 安徽理工大学 ， 安全技术及工程， 2010， 硕士
【摘要】 作为一种区域性防突措施,一般在条件允许的情况下都把开采保护层作为首选的防突措施。新集煤矿C13-1煤层具有煤与瓦斯突出危险性,在这种情况下,选择首先开采其下方平均间距为65米的不具有突出危险的B11-2煤层,通过采动影响造成C13-1煤层卸压,以降低其突出危险性。本文在保护层开采理论分析基础上,针对新集矿区煤层赋存地质条件,采用相似材料模拟试验的方法研究了开采过程中随着工作面的推进覆岩移动破坏特征和煤岩体内应力分布规律；利用数值模拟的方法研究了保护层开采影响下覆岩的应力变化和塑性区分布范围以及护巷煤柱对卸压范围的影响等；通过现场实测考察了随工作面的推进被保护层瓦斯压力变化规律、透气性变化规律、被保护层在采动影响下的膨胀变形规律和卸压瓦斯抽放效果等。现场实测结合相似模拟和数值模拟结果得出被保护层卸压范围,下保护层的开采对被保护层的卸压范围沿走向方向卸压角为55°,沿倾斜方向上山卸压角为86°,下山方向卸压角为69°,在保护范围内应力下降,被保护煤层膨胀变形,其变形率最大达20.42%,煤层透气性大大增强,透气性系数相比开采前原始透气性系数增大了近1000倍,保护层开采取得了良好的效果。
【Abstract】 Exploitation of the protective layer has been increasing attention as a regional anti-surprise measures, generally, if conditions permitting protective layer mining regarded as the preferred anti-sudden measures. C13-1 coal seam of xin-ji mine with coal and gas outburst danger, in this case, select the B11-2 coal seam as the first exploitation, through the mining-impact caused C13.1 Coal pressure relief to reduce the risk of its prominence.This paper based on the theoretical analysis of the protection layer exploitation against geological conditions of coal seam of xin-ji mine, through the similar simulation test researched the law of movement-destruction and stress distribution of overlying strata with the advancing of the working face; through numerical Computing researched the stress variation and the plastic zone distribution of the overlying strata in the under-protective B11-2 coal seam mining etc.; through measurement on locale-site reviewed the layer of gas pressure change of protected layer and variation of permeability and pressure relief gas drainage effects with the face of the advancing, and combined field measurement and numerical simulation and similar simulation results obtained the relief angle 55°of protective layer along the direction of advancing and the uphill relief angle 86°and downhill relief angle 69°of the inclined direction, after under-protection layer mining the stress drop in the scope of protection and the protected coal deformed and expanded, its maximum deformation ratio is 20.42%, fully seam permeability after stress-relief greatly enhanced,permeability coefficient of expansion of the nearly 1000 times,the protective-layer mining obtained well effects.