煤体水力化措施综合消突作用研究
Study on comprehensive outburst elimination effect of hydraulic measures applied to coal mass
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摘要: 为了研究水力化措施的综合消突作用,在综合分析水力化措施作用效应的基础上,将水力化措施归结为致裂类和掏槽类,结合煤与瓦斯突出综合作用假说,分别从水力化措施对煤体卸压效应、瓦斯内能以及煤的物理力学性质3个方面的影响进行了分析。结果表明:水力化措施能够降低一定范围内煤体的载荷应力;煤体吸附瓦斯受到环境气体压力的变化和水分的竞争吸附影响,发生了降压解吸和置换解吸,水分置换了59.14%的吸附瓦斯,降低了瓦斯内能;采取水力措施后煤体水分增加,弹性模量能够降低58.69%,塑性指数增大4.3倍以上,降低了煤体弹性能。水力化措施能够降低煤体承载应力、瓦斯内能和煤体弹性能,对煤层消突具有综合作用。为进一步提高水力化措施综合消突效果,提出执行水力化措施时,应考虑在注入的水中加入活性剂,增强煤体的湿润效果,致裂类措施还应采取卸压孔来消除裂缝尖端应力集中效应。Abstract: In order to study the comprehensive outburst elimination effect of the hydraulic measures, based on the comprehensive analysis on the applied effect of the hydraulic measures, the hydraulic measures could be a fracturing type and an open cut type. In combination with the hypothesis on the comprehensive effect of the coal and gas outburst, an analysis was conducted on the hydraulic measures affected to the pressure released effect of the coal mass, gas internal energy and coal phy sical property.The results showed that the hydraulic measures could reduce the load stress of the coal within a certain scope.The adsorbed gas of the coal mass would be changed by the environment gas pressure and would be affected by the moisture competitive adsorption, a pressure released and adsorption and the replaced adsor ption would be occurred, the water content could replace 59.14% of the absorbed gas and the gas internal energy would be reduced. After the measures applied, the m oisture content of the coal mass would be increased, the elastic modulus could be reduced by 58.69%, the plastic index could be increased over 4.3 times and the elast ic energy of the coal mass would be reduced.The hydraulic measures could reduce the load stress of the coal mass, gas internal energy and elastic energy of the coal mass and would have a comprehensive effect to the outburst elimination of the seam.In order to further improve the comprehensive outburst eliminated effect of the hyd raulic measures, during the hydraulic measures completed, an activator injected into the water should be considered to enhance the moisture effect of the coal mass.Th e fracturing type measures should have the pressure released borehole to eliminate the stress concentration effect at the crack tip.