类孤岛工作面复采方案优选分析研究

Analysis study on selective preference of recovery mining project for island-like working face

孤岛工作面是我国煤炭开采的一个技术难题,强矿压显现是孤岛工作面的重要特征,下石节煤矿类孤岛工作面因采动矿压显现剧烈而停采封面。为实现资源有益回收,延长矿井剩余服务年限,实现该类孤岛工作面安全复采,在综合现场调研、数值模拟计算以及理论分析等方法的基础上,总结分析了220工作面动压显现特征及其发生机制,提出了220工作面扩面和缩面2种改造方案,并综合对比评价了2种复采方案的动压、水、火、瓦斯防治的危险性以及经济效益情况。研究结果表明:220工作面动压显现与周期来压、顶板活动紧密相关,超高应力、上位多层厚硬岩层、宽煤柱以及频繁煤炮等综合作用是矿压剧烈显现的根源。确定了扩面改造(内错2301采空区15 m)、缩面改造(缩短50 m)为最优复采方案。综合对比2种复采方案的整体风险性以及经济效益情况建议:220工作面采用缩面50 m进行复采,安装简易机头、机尾单电机的综放推移方式,视情况再决定是否替换过渡支架以及安装正规机头和电机。

Island working face is a technical problem of coal mining in China,strong ground pressure behavior is significant characteristic of island working face,the island-like working face in Xiashijie Coal Mine stopped mining and closed working face due to strong mining pres⁃sure behavior.In order to realize the beneficial recycling of resources,extend the remaining service life of the mine,and realize the safe remining of the island-like working face,on the basis of comprehensive site survey,numerical simulation calculation and theoretical analysis,this paper summarizes and analyzes the dynamic pressure behavior characteristics and its mechanism of No.220 working face,and puts for⁃ward two kinds of transformation schemes of No.220 working face expansion and contraction.The results show that the dynamic pressure be⁃havior of No.220 working face is closely related to periodic roof weighting and roof activity,and the comprehensive effects of super-high stress,upper multi-layer thick and hard rock,wide coal pillar and frequent coal blasting are the root of strong mining pressure behavior.The optimal re-mining schemes is determined as expanding face reconstruction(15 m in internal displacement Goaf 2301)and reducing face reconstruction(shorten by 50 m).By comprehensively comparing the overall risks and economic benefits of the two mining schemes,it is suggested that the fully mechanized top coal caving mining should be carried out in the No.220 working face with a reduced face of 50 m,and a simple machine head and a single motor at the tail should be installed,and whether to replace the transition support and install the regular machine head and electric machine should be decided according to the situation.