岩石峰后蠕变试验及其在沿空留巷底鼓研究中的应用

    Experimental Study on Floor Heave in Stable Stage of Gob-side Entry Retaining

    • 摘要: 为了得到沿空留巷稳定阶段的底鼓机理与控制对策,通过岩石峰后蠕变试验,分析了损伤程度和围压增量对岩石峰后蠕变性态的影响。结果表明:岩石峰后蠕变破坏形式是类“X”状剪切破坏,破坏后块体会沿破裂面发生较大滑移;峰后岩石损伤程度越小,其蠕变速率越小,可以保持自稳的时间越长;提高围压可以减小峰后岩石实际承受的等效应力,进而改善其蠕变性态,相反,围压降低则会恶化其蠕变性态。最终得到:沿空留巷留巷稳定阶段底鼓的主要形式是底板破裂区峰后岩体的蠕变变形与其蠕变失稳后破坏块体沿破裂面的滑移。

       

      Abstract: In order to obtain the mechanism and control countermeasures of floor heave in stable stage of gob-side entry retaining, creep test of post-failure rock is performed to study the impact of damage degree and confining pressure increment on creep properties of post-failure rock. The results showed that: the smaller damage degree of the post-failure rock, the smaller of its creep rate and the longer of its self-stability time; the increase of confining pressure can reduce the practical bearing equivalent stress of the post-failure rock and then improve its creep properties. The paper draws a conclusion that the form of floor heave in stable stage of gob-side entry retaining roadway is creep deformation of post-failure rock in floor fracture region and slippage of displaceable blocks along failure surface.

       

    /

    返回文章
    返回