煤层群上下保护层开采围岩应力及裂隙演化规律研究  

Study on the stress and fracture evolution law of surrounding rock during mining of upper and lower protective layers in coal seams

作　　者：刘军 LIU Jun(CCTEG Chongqing Research Institute,Chongqing 400037,China;State Key Laboratory of Coal Mine Disaster Prevention and Control,Chongqing 400037,China)

机构地区：[1]中煤科工集团重庆研究院有限公司,重庆400037 [2]煤矿灾害防控全国重点实验室,重庆400037

出　　处：《矿业安全与环保》2024年第4期56-63,73,共9页Mining Safety & Environmental Protection

基　　金：国家自然科学基金青年项目(52204261);重庆市自然科学基金面上项目(CSTB2023NSCQ-MSX057)。

摘　　要：为实现煤层群上下保护层开采过程中被保护层卸压瓦斯的高效抽采,采用数值模拟方法研究上下保护层开采后围岩应力、裂隙分布及演化规律,探明上下保护层开采的卸压瓦斯富集区。研究结果表明:下保护层开采后,被保护层工作面上侧覆岩卸压高度明显大于下侧覆岩卸压高度,次采上保护层后,增大了被保护层卸压范围。下保护层开采后被保护层走向卸压角为63°,倾斜上下边界卸压角为87°、72°。上保护层开采后被保护层走向卸压角为59°,倾斜上下边界卸压角为76°、79°。经过保护层卸压后,被保护层抽采卸压瓦斯纯流量相比卸压前呈现10余倍增大,卸压瓦斯抽采具有明显的时空效应。To achieve efficient gas extraction from the pressure relief of the protected layer in the upper and lower protective layers of coal seam groups,numerical simulation methods were used to study the distribution and evolution of surrounding rock stress after the upper and lower protective layer mining.The depressurized gas rich area of upper and lower protective layer mining was identified.The results show that after mining,the lower protective layer and the pressure relief height of the overlying rock on the upper side of the working face are both significantly higher than in the lower side.After mining the upper protective layer again,the pressure relief range of the protected layer is increased.After the mining of the lower protective layer,the pressure relief angle of the protected layer is 63°.The inclined upper and lower boundary pressure relief angles are 87°and 72°,respectively.After mining the upper protective layer,the pressure relief angle of the protected layer is 59°.The inclined upper and lower boundary pressure relief angles are 76°and 79°,respectively.After the protective layer is depressurized,the net amount of gas extraction increases by dozens of times before the depressurization.The depressurized gas extraction has a significant spatiotemporal effect.

关 键 词：煤层群 保护层 围岩应力 采动裂隙 演化规律 卸压瓦斯 

分 类 号：TD712[矿业工程—矿井通风与安全]