摘要
为研究下保护层开采上覆煤层应力演化及渗透率演化规律,以轿子山煤矿8煤和9煤为研究对象,运用COMSOL建立煤层开挖模型,研究下保护层顶板应力演化及8煤和9煤渗透率变化规律,并进行现场试验验证。结果表明:随着保护层的持续推进,工作面前端应力集中达到了8 MPa左右,与原始应力对比增加了8倍;保护层开采至80 m时,8煤渗透率从2.8×10^(-17)m^(2)增加到4.0×10^(-17)m^(2),9煤渗透率从2.6×10^(-17)m^(2)增加至16×10^(-17)m^(2),分别增加了71.67%和586.70%;8煤瓦斯抽采数据显示,保护层开采使瓦斯抽采量提升了14倍左右,瓦斯抽采峰值流量达到35 m^(3)/min。保护层推进80m以后,受煤岩自重影响,煤层裂隙出现闭合,瓦斯抽采量下降至25 m^(3)/min左右。钻孔窥视表明,保护层开采影响40 m左右煤岩,该结果与数值模拟结果类似。
In order to study the stress evolution and permeability evolution law of overlying coal seams in the lower protectiveseam mining,taking the No.8 and No.9 coal seam in Jiaozishan Coal Mine as the research objects,COMSOL was used toestablish the coal seam excavation model,and the stress evolution law of the roof in the lower protective seam and the permeability changes of No.8 and No.9 coal seams were studied.The field test was carried out to verify the results.The results show that with the continuous advancement of the protection layer mining,the stress concentration at the front end of the working face reaches about 8 MPa,which is 8 times higher than the original stress,As mining to 80 m,the permeability of No.8 coal seam increases from 2.8×10^(-17)m^(2) to 4.0×10^(-17) m^(2),and the permeability of No.9 coal seam increases from 2.6×10^(-17)m^(2) to 16×10^(-17)m^(2),with a increase rate of 71.67%and 586,70%respectively.The gas extraction in No.8 coal seamshow that protective layer mining can increase the gas extraction by about 14 times,and the peak flow of gas extraction reaches35 m^(3)/min.After the protective layer is advanced by 80 m,the coal seam cracks are closed due to the influence of the weight ofthe coal and rock,and the gas extraction rate will decrease to about 25 m^(3)/min.Borehole observation shows that the effect range of protective layer mining on the coal and rock is about 40 m,which is similar to the numerical simulation results.
作者
焦安军
田世祥
林华颖
邱芝鑫
郭国明
许石青
余婕
JIAO Anjun;TIAN Shixiang;LIN Hua ying;QIU Zhixin;GUO Guoming;XU Shiqing;YU Jie(Mining College,Guizhou University,Guiyang,Guizhou 550025,China;The Emergency Management Bureau of Zhijin County,Bijie,Guizhou 552100,China)
出处
《矿业研究与开发》
CAS
北大核心
2022年第2期24-30,共7页
Mining Research and Development
基金
贵州省科技厅项目(黔科合支撑[2019]2887号).
关键词
煤
保护层开采
应力演化
瓦斯含量
渗透率
Coal
Protective layer mining
Stress evolution
Gas content
Permeability
作者简介
焦安军(1998—),男,贵州凯里人﹐硕士研究生,主要从事安全科学与矿井瓦斯灾害防治研究,E mail:jj182204759@gmail.com;通信作者:田世祥(1988—),男,贵州镇远人,博士,讲师,主要从事矿井瓦斯灾害防治教学与研究工作,E-mail:husttsx(@163.com.
