Application analysis of sensitive index in predicting abnormalgas emission from coal seam

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.