注水对顶煤强度及冒放性的影响机理研究

针对注水后煤层强度降低及顶煤冒放性增加的机理,引用Mohr-Coulomb强度准则构建水理性分析模型,并采用大量煤样岩石力学试验方法,分析了水对煤体单轴抗压强度和剪切参数的影响作用,得出了降低煤体强度、增加顶煤的冒放性与煤层注水水压力和孔隙压力系数的关系,分析了煤层注水对顶煤强度及冒放性的影响因素。结合碱沟煤矿急倾斜坚硬特厚煤层综放开采条件,进行了顶煤注水弱化试验,验证了模型的合理性。

Analysis on influence mechanism of water injection on top-coal strength and drawing properties

Through mechanism of strength reduction and top coal caving increasing after water injection on coal seam, this paper establishes watery analysis model referring to Mohr-Coulomb strength criterion and analyses the effect of water to coal uniaxial compressive strength and shear parameters. It also ana- lyses the relationship between result of strength reduction and top coal caving increasing and water pres-sure and pore pressure. Besides, the influential factors of water injection to the top coal strength and caving properties are analyzed. Combined with conditions of Jian-gou coal mine＇ s fully mechanized mining face in inclined hard thick seam, it has the top coal weakening of water injection test and validates the rationality of the model.