摘要
针对冲击发生后瓦斯异常涌出的现象,分析了煤岩微裂隙状态、温度等因素在冲击地压发生前后的变化以及冲击地压引起矿体震动对瓦斯吸附能力的影响,从多角度分析了冲击地压发生后导致瓦斯异常涌出的条件和原因。通过理论计算,瓦斯渗透试验等手段,研究了煤体受载过程中孔隙度和渗透性的变化规律;在含气煤本构方程的基础上,利用三轴加载条件下应力-渗透率关系计算得到了煤样加载过程中的渗透率的变化曲线。结果表明:冲击地压的发生确实存在导致瓦斯异常涌出的条件,而瓦斯对煤体存在力学和非力学的作用,可以导致煤体强度下降,脆性增强,并能够加速煤体的失稳破坏;煤体孔隙度和渗透率在三轴加载条件下会有先降低后增大的趋势,在应力达到破坏载荷的70%左右时,孔隙度和渗透率急剧增长;煤岩体内裂纹扩展,渗透性能增加是高瓦斯矿井冲击地压发生后瓦斯大量涌出的最直接的原因,矿体震动、煤岩体温度升高等冲击地压的伴生现象在一定程度上会促进瓦斯解吸和逸出。
To explain the phenomenon that the gas spurt which emerged after the coal bump, the variation before and after the coal bump including the microfractures in the coal and rock mass, the temperature, etc. were analyzed, also the influence of the mine seismic induced by the coal bump to gas adsorptive ability was analyzed, and gave the reasons why the phenomenon exists from multi-angle. The variation of the porosity and permeability of the coal under loading were researched by theoretical calculation and test of the gas permeability. Based on the constitutive equation of the gas coal, obtained the permeability curve of the coal under loading by using the relationship of stress-permeabili- ty under triaxial compression tests. The results show that the coal bump makes it possible for the gas to spurt, and the mechanical or non-mechanical effects given by the gas cause the descend of the strengthen but the ascent of the fragili ty of the coal and accelerate the deformation of the coal at the same time. The coal＇ s triaxial compression tests show that its porosity and permeability have a tendency to reduce first and then to increase, and they will raise shapely when the stress is up to 70% of the failure load. The expand of the microfractures in the coal and rock mass and the increase of the permeability are the most direct causes for the numerous gas spurt after the coal bump in the coal mine with massive gas. The associated phenomenon with the coal bump like mine seismic and the temperature of the rock mass increasing stimulate the desorption and release of the gas.
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2014年第2期371-376,共6页
Journal of China Coal Society
基金
国家重点基础研究发展计划(973)资助项目(2010CB226801)
煤炭资源与安全开采国家重点实验室开放基金资助项目(SKLCRSM11KFB08)
中国博士后科学基金资助项目(2013M530770)
关键词
冲击地压
瓦斯
次生灾害
吸附解吸
渗透率
coal bump
gas
secondary disaster
absorption and desorption
permeability
