沿空掘巷非对称性差异化支护技术研究

Application of Asymmetric Differential Support Technology in Gob-side Entry Driving

为解决沿空掘进巷道受采空区侧应力影响作用大,巷道围岩控制难度大、易变形,巷道维护及安全管理难度大等问题,以余吾煤业公司N1105综采工作面回风巷为工程背景,采用FLAC3D软件进行数值模拟分析,确定出采空区侧煤柱留设宽度为8 m,并结合巷道地质条件及现场开采实际情况,提出沿空掘巷非对称性差异化支护技术。通过对在相同地质条件下对称性支护方式和非对称性差异化支护方式巷道围岩应力变化及塑性区分布特征进行模拟分析得出:非对称性差异化支护方式下巷道煤柱侧围岩应力集中范围更小,其应力集中区范围在距巷帮2~3 m左右,煤柱帮围岩塑性区范围比对称性支护方式下减小约2.0 m。应用结果表明:工作面回风巷在掘进90 d后,巷道围岩变形基本趋于稳定状态,巷道顶板下沉量、实煤体帮和煤柱帮巷帮移近量分别为275、230、280 mm左右,围岩变形量在允许可控范围内。

In order to solve the problems that roadway driving along goaf is greatly influenced by the lateral stress of goaf,the surrounding rock of roadway is difficult to control and deform,and the roadway maintenance and safety management are difficult,taking the return air roadway of N1105 fully mechanized mining face of Yuwu Coal Company as the engineering background,numerical simulation analysis is carried out by FLAC3D software,and it is determined that the width of coal pillar on the side of goaf is 8 m.Combined with the geological conditions of roadway and the actual situation of field mining,the asymmetric differential support technology for roadway driving along goaf is proposed.Based on the simulation analysis of the stress change and plastic zone distribution characteristics of roadway surrounding rock under the same geological conditions,it is concluded that the stress concentration range of roadway surrounding rock at the side of coal pillar is smaller under the asymmetric differential support mode,and the stress concentration range is about 2~3 m away from the roadway wall,and the plastic zone range of coal pillar wall is about 2.0 m smaller than that under the symmetric support mode.The application practice results show that the surrounding rock deformation of the return air roadway in N1105 Working face tends to be stable after 90 days of excavation,and the roof subsidence,solid coal body and coal pillar side drift are about 275,230、280 mm respectively,and the surrounding rock deformation is within the allowable and controllable range.