Study On Sensitivity Index And Critical Value Of Outburst Prediction Of Two₂ And Three₂ Coal Seams In Xinzhuang Coal Mine

China's coal seam conditions are complex,and coal and gas outburst accidents occur from time to time,which seriously restricts the safe and efficient production of coal in China.How to make reliable predictions of coal and gas outburst hazards,reduce the amount of outburst prevention projects,and ensure safe production of coal mines is the top priority for preventing coal and gas outbursts.In the actual production of Xinzhuang Coal Mine,the two₂ and three₂ coal seams are predicted and their critical values refer to the"Details on Prevention of Coal and Gas Outbursts",which is prone to the phenomenon of"high indicators not protruding,bottom indicators prominent".The prominent prediction sensitive indicators and critical value determination for the two₂and three₂ coal seams in Xinzhuang Coal Mine can make the prediction of the mining process in Xinzhuang Coal Mine more efficient and accurate,which is of great significance for ensuring the safety of mine production.This article analyzes the gas occurrence rules and geological structure of Xinzhuang Coal Mine,determined the coal seam floor elevation and burial depth as the main controlling factors of mine gas,conducted on-site tracking test on the forecast indicators and obtained 832 sets of forecast data.The criticality analysis of variance and gray correlation analysis were used to determine the dispersion and sensitivity of the predictive indicators,Therefore,the sensitivity order of outburst prediction indexes of the two₂ and three₂ coal seams in Xinzhuang Coal Mine is determined as:q>?h₂>K₁>S.Study on the adsorption and desorption law of the two₂ and three₂ coal seams in Xinzhuang Coal Mine by collecting coal samples,Through the laboratory analyzed the relationship between different equilibrium pressures and prediction indicators.Combined with the"three rate method"analysis,the critical values of the sensitive prediction indicators for the two₂ and three₂ coal seams in Xinzhuang Coal Mine were determined.It was finally determined that the initial velocity q of borehole gas emission during the prediction of the outburst hazards of the two₂ and three₂ coal seams in Xinzhuang Coal Mine can be used as the main sensitive index.The critical values are5.00L/min and 5.34L/min,respectively,and the cuttings analysis index?h₂ and K₁ can be used as an auxiliary sensitive indicator.The critical values are 180Pa?200Pa and0.40mL/(g·min^1/2)?0.45mL/(g·min^1/2)?This thesis consists of 28 pictures,28 tables and 67 references.