敏感指标预测煤层瓦斯异常涌出应用分析
Application analysis of sensitive index in predicting abnormalgas emission from coal seam
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摘要:
为探索掘进工作面瓦斯异常涌出规律,判断掘进工作面前方瓦斯涌出量大小,在瓦斯异常涌出区域预先采取防治措施,选取钻屑量、钻屑瓦斯解吸指标Δh2、K1为敏感指标,确定敏感指标测定钻孔布孔方式,并通过理论计算确定敏感指标初值。在某矿掘进工作面不同区域测定敏感指标数值,将测定的数据采用灰色关联分析法计算得出钻屑量指标敏感性最高,确定采用钻屑量作为敏感指标预测瓦斯异常涌出区域,采用模糊统计法确定敏感指标临界值。结合掘进当期瓦斯涌出量数据,分析钻屑量与瓦斯涌出量之间的关系,拟合建立钻屑量-瓦斯涌出量函数,采用钻屑量对未掘区域掘进期间瓦斯涌出量大小的判断。结果表明,某矿瓦斯涌出量最大预测值为4.90 m3/min,瓦斯涌出量与钻屑量呈正相关关系,由此预测当钻屑量超过4.40 kg/m,瓦斯涌出量为3 m3/min。在瓦斯异常涌出区域预先开展瓦斯防治措施,可以确保掘进期间安全生产。
Abstract:In order to explore the law of abnormal gas emission in the heading face and judge the amount of gas emission in front of the heading face, preventive measures are taken in advance in the area of abnormal gas emission.Selecting the amount of drilling cuttings and gas desorption index of drilling cuttings Δh2 and K1 are sensitive index.Determining the borehole layout and the initial value of sensitive index through theoretical calculation.The sensitive index values are measured in different areas of the heading face of a mine.The measured data are calculated by the grey correlation analysis method.It is concluded that the sensitivity of the drilling cuttings index is the highest.It is determined to use the drilling cuttings as the sensitive index to predict the abnormal gas emission area.The critical value of sensitive index is determined by fuzzy statistical method.Combined with the gas emission data in the current period, the relationship between the amount of drilling cuttings and the amount of gas emission is analysed, and the function of drilling cuttings and gas emission is fitted and established.Realizing the judgment of gas emission during tunnelling in the non excavated area by using the amount of drilling cuttings.The maximum prediction value of gas emission in a mine is 4.90 m3/min, and there is a positive correlation between gas emission and drilling cuttings.It is predicted that when the amount of drilling cuttings exceeds 4.40 kg/m, the gas emission is 3 m3/min.Gas prevention measures shall be taken in advance in the area with abnormal gas emission to ensure safe production during excavation.