保护层开采条件下煤层力学扰动规律及抽采半径考察  

Investigation on Mechanical Disturbance Law and Extraction Radius of Coal Seam under Condition of Protective Seam Mining

作　　者：崔聪 马延崑 舒龙勇 李宏艳[1,2] CUI Cong;MA Yankun;SHU Longyong;LI Hongyan(China Coal Research Institute,Beijing 100013,China;State Key Laboratory of Coal Mining and Clean Utilization,China Coal Research Institute,Beijing 100013,China)

机构地区：[1]煤炭科学技术研究院有限公司,北京100013 [2]煤炭资源高效开采与洁净利用国家重点实验室(煤炭科学研究总院),北京100013

出　　处：《煤炭技术》2023年第2期61-65,共5页Coal Technology

摘　　要：为分析新集一矿6-1煤在上保护层开采条件下煤层力学扰动特征及煤层抽采半径,根据采场分布及力学参数建立了几何模型,进行360804工作面的开挖模拟计算,结果表明,6-1煤体经历应力升高—峰值状态—降低—趋于初始状态恢复的过程,6-1煤经历透气性降低—急剧增长—逐渐降低的过程,工作面累积推进198 m时,采空区形成“见方”状态,下方煤体透气性系数急速增长,推进360 m时,采空区中部地应力恢复,透气性系数减小,形成一个“O”形高透气性区域;结合现场实际情况,建立了4种网格式钻孔布置方式,通过数值模拟及现场测试方法考察了被保护层抽采半径,结果表明4种布置方式12个月抽采条件下,瓦斯压力有显著降低,20 m网格间距效果最佳。当采用20 m×20 m网格式抽采下伏6-1煤层瓦斯,历经12个月抽采量达到134.94万m^(3),划定保护范围内6-1煤层平均瓦斯含量由3.62 m^(3)/t降低至2 m^(3)/t,煤层瓦斯预抽率达到了39.8%,煤体瓦斯可解吸量1.5 m^(3)/t。In order to analyze the mechanical disturbance characteristics of coal seam and the relationship with the extraction radius of coal seam 6-1in Xinji No.1 coal mine under the condition of upper protective seam mining,according to the stope distribution and mechanical parameters,the numerical model is established,and the excavation simulation of 360804 working face is carried out.The mechanical disturbance law of the protected seam under the condition of mining protective seam is analyzed.It shows that 6-1coal body experiences the process of stress increase-peak state-decrease initial state recovery,and 6-1coal body experiences the process of permeability decrease-rapid growthgradually decrease.When the cumulative advance of the working face is 198 m,the goaf forms a"square"state,and the permeability coefficient of the coal below increases rapidly;when advancing 360 m,the in-situ stress in the middle of the goaf recovers and the permeability coefficient decreases,forming an"O"shape high permeability area.Four kinds of grid are established.The results show that under the condition of 12-month drainage,the gas pressure is significantly reduced,and the effect of 20 m grid spacing is the best.When using 20 m×20 m grid the underground 6-1coal seam gas is extracted,after12 months,the gas extraction amount reaches 1.3494 million m^(3).The average gas content of 6-1coal seam within the protection scope is reduced from 3.62 m^(3)/t to 2 m^(3)/t,the gas pre drainage rate of coal seam reaches 39.8%,and the gas desorption amount of coal body is 1.5 m^(3)/t.

关 键 词：力学扰动 抽采半径 保护层开采 透气性系数 衰减系数 

分 类 号：TD322[矿业工程—矿井建设] TD325TD712