煤与瓦斯共采覆岩应力及渗透耦合特性实验研究

为探索煤层开采过程中上覆岩体应力与其渗透性相互耦合特性，开展了煤与瓦斯共采相似模拟实验研究。采用柔性加载方式以及平面应变模型，模拟随工作面推进上覆围岩应力及渗透性的变化规律。结果表明：受采动影响，上覆围岩应力与渗透率变化呈现一定的分区特征。具体表现为，随采面推进，煤柱后方应力集中区域向远离采空区转移，应力集中系数降低，渗透率与压应力分布呈正相关关系；远离采空区向高位延伸方向，应力降低幅度有递减趋势，有明显应力拱向高位及广度扩展特征，当达到充分采动时，此特征趋于减弱；提出覆岩渗透规律具有“拱上梁”的假设特征，即在拱顶位置，渗透率有不升反降趋势。

Experimental study on coupling of stress and permeability in overlying strata at longwall panel for efficient coal and methane co-extraction

In order to understand the coupling characteristics of stress and permeability in overlying strata，an analog experimental simulation was conducted to study the co extraction of coal and methane in longwall coal mine.The experiment used a plane strain model and flexible loading to simulate the variation characteristics of stress in overly strata and permeability in advanced coal face.The results show that a partition tendency exists：with the coal face advancing，the concentration area of stress inside coal pillar removes away from the gob，the coefficient of concentration desceases，and the permeability and stress demonstrates a direct proportional relationship.The range of stress decrease experiences a tendency of slow in the direction from goaf to high position.In addition，the stress arch expands vertically and horizontally at the same time，while it will recede at a fully extraction phase.