顶板浅部裂隙通道演化规律与分布特征

为得出顶板裂隙通道的演化过程和空间分布特征，以岩体力学和煤岩全应力-应变过程中瓦斯流动变化规律为理论基础，采用深部位移自动监测仪和裂隙通道巡回摄录仪，进行理论分析和现场测试研究，得出了瓦斯裂隙通道形成判据和分布特征。结果表明：煤岩分层成为瓦斯裂隙通道边界需要满足其变形小于下分层或大于上分层，同时其稳定跨距大于顶板悬露距离，据此判别出试验矿区顶板浅部主干裂隙通道位于顶板上方1.5，5.0 m处；随工作面推进，顶板裂隙通道经历原生裂隙通道主导阶段、裂隙通道产生、扩张、成熟和闭合阶段的演化过程，重新压实区至工作面前方原岩应力区距离与工作面日推进速度的比值为裂隙通道的演化周期，试验矿区演化周期为11～14 d。

Evolution and distribution characteristics of roof shallow fissure channel

In order to figure out evolutionary process of roof fissure channel and spatial distribution characteristics，based on rock mechanics and gas flow variation of coal and rock stress strain process，using deep displacement automatic monitor and fissure channel itinerant video camera，theoretrical analysis and field testing were done and the formation criterion of gas fissure channel and distribution characteristics were obtained.The results show that the coal rock stratification becomes gas fissure channel when the transformation is smaller than lower stratification or bigger than upper stratification and the stable span must be bigger than roof exposure length，according to this，the roof shallow fissure channel of test mine is located 1.5 m and 5.0 m above the roof；with working face promoting，roof fissure channel goes through an evolutionary process：pre existing fissures channel dominant stage and fissure channel produce expand mature close stage，the evolutionary cycle of fissure channel is the ratio of the distance between re compaction area and initial stress area in front of working face and the promoting speed per day，and the evolutionary cycle of test mine is 11-14 days.