考虑剪胀及软化特性的煤层瓦斯含量测定最小取样深度研究

Study on Minimum Sampling Depth of Coal Seam Gas Content Determination Considering Dilatancy and Softening Theory

为确定合理的煤层瓦斯含量测定取样深度,建立考虑剪胀及软化特性的巷道周围煤体弹塑性模型,得到了煤层瓦斯含量测定取样最小深度的表达式,并进行实际验证,分析了取样深度的主要影响因素。结果表明:控制最小取样深度的主要因素为初始地应力、支护应力、煤体强度和巷道尺寸;埋藏深度越大,取样深度应越长;煤质越软,取样深度应越长;取样深度随支护应力的减小而增大;在大断面巷道,应增加取样深度。

To determine the reasonable minimum sampling depth of coal seam gas content determination,the elastic-plastic model of coal body around the tunnel considering the characteristics of dilatancy and softening was established,the expression of the minimum sampling depth of the coal seam gas content was obtained and the actual verification was carried out. The main influencing factors of determining the sampling depth were analyzed. The results show that： the main factors controlling the minimum sampling depth are the initial stress,supporting stress,coal strength,and tunnel radius. The burial depth is deeper and the coal is softer,the sampling depth should be longer; the sampling depth should increase in large section roadway and the depth of the sample should increase with the decrease of support stress.