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为研究采动应力对煤体渗透率的影响,采用渗流实验和理论分析的方法,对2个矿的2组煤样在2种采动应力下的渗流特性进行了研究,并揭示了渗透率变化规律。结果表明:2种采动应力下渗透率整体变化规律相似,但各阶段渗透特性不同;在准静水压力阶段,渗透率都随应力增加而下降,保护层采动应力下的渗透率总体大于放顶煤;在第二加卸载阶段,放顶煤采动应力下渗透率呈现缓慢上升,水平应力卸载对渗透性系数影响起主要作用,而保护层采动应力下是阶段末期才开始上升;2种采动应力下渗透率呈现低速增长、增长和高速增长阶段,特别在工作面应力峰值点后,进行抽采效果较理想。
In order to study the influence of mining stress on the permeability of coal, the seepage experiment and theoretical analysis were used to study the seepage characteristics of two coal samples in two mines under two kinds of mining stress. The permeability The law of change. The results show that the permeability changes under two kinds of mining stress are similar, but the permeation characteristics are different in each stage. During the quasi-hydrostatic pressure stage, the permeability decreases with the increase of stress, and the permeability under the protective layer mining stress is larger than that In the second stage of loading and unloading, the permeability of caving coal slowly increases under the stress of caving, and the unloading of horizontal stress plays a major role in the influence of permeability coefficient, while the capping stress of protective layer does not begin to rise until the end of the stage. 2 Under the mining stress, the permeability shows a slow growth, growth and high-speed growth stage, especially after the stress peak of the working face, the pumping effect is better.