顶板岩性组合结构对逆断层活化特征研究

为了减少断层活化对煤炭安全生产带来的威胁,本文以河南某矿11011工作面过断层为工程背景,通过FLAC~(3D)三维数值模拟软件和微震监测等方法,研究了在不同顶板岩性组合结构下,工作面向逆断层推进时,煤层顶板的运动特征、断层带应力演化规律以及工作面过断层期间微震事件特征。研究表明,断层受到的开采扰动随工作面推进而逐渐增加,活化程度也越剧烈,在距断层10～20m时,断层活化危险性最大;受工作面回采的影响,顶板不同岩性组合结构下,断层发生活化难易程度为:软硬硬软软软硬硬硬软软硬硬硬软软;在工作面回采过程中,断层带B监测点的相对下沉量大于监测点A,说明断层上方高位处先发生活化失稳;随着工作面不断接近断层,断层受开采扰动的影响也越大,断层附近区域岩体微裂隙越多,断层附近区域微震事件越多,断层活化越剧烈。研究成果为断层发育区煤炭资源安全开采提供理论依据与技术参考。

Study on activation characteristics of reverse faults by lithologic composite structures of roof

Abstract: In order to reduce the threat of fault activation to coal safety production, this paper takes the 11011 working face of He Nan Mine of a mine in He Nan province as the engineering background, and studies the lithologic composite structure under different roofs by FLAC3D three-dimensional numerical simulation software and microseismic monitoring. When the work is oriented to the reverse fault, the movement characteristics of the coal seam roof, the evolution law of the fault zone stress and the characteristics of the microseismic events during the fault crossing of the working face The research shows that when the working face is close to the fault, the fault is gradually affected by the mining disturbance, and the degree of activation is gradually increased. When the fault is 10-20m away, the stress of the fault zone changes significantly, and the degree of activation is the greatest: affected by the mining face Under the different lithological combination structures of the roof, the difficulty of activation of the fault is: soft and hard and soft