On The Determining Method Of Sensitivity Indexes For Coal/Gas Outburst Forecast And The Confirming Of Critical Value For Regions

Coal and gas outburst is a complacate dynamic phenomenon, and a natural calamity which seriously threaten the mine production security. The key of coal and gas outburst forecast is screening out the right sensitive index from so many outburst forecast indexes,commonly used current method is the three rates rule and gray relational analysis.Three rates rule's process is clear and easy to understand, and calls for the outburst dynamic phenomena record in detail,and the determining of the outburst dynamic phenomena depend on the experience of the workers,mistake is usual.Although the gray relational analysis method avoid a three rates rule's fuzzy determination of the dynamic phenomena, but the data processing complex, not suitable for application in the field to promote the production. Aimed at the above lack of determining sensitive indexes,reasch is done as follow:1,Base on coal and gas outburst mechanism and occur conditions,this paper comprehensivly analyze the current application status, measurement methods and the prominent factor reflected by indexes. 2,Have tried on using Principtal Component Analysis on screening of coal and gas outburst prediction index. Through analysising principal component theory, combined with the characteristics of outburst predict index, discussed the feasibility of the principal component analysis used in the coal and gas outburst prediction index screening. Analysis a batch of measured data of a coal mine by three rates rule,gray correlation analysis and principal component analysis were prominent predictor of sensitivity ranking, the conclusions of three methods is consistent. This prove the reliablity of Principal component analysis used on demonstrated prominent predictor of sensitivity.3,For the coal mine which has lardge range and complex geological conditions, this paper suggest that the coal ming shoule be divided into several small range according to the outburst factor reflected by outburst proforst indexes, and then confirm different critical values of the desorption index for regions. In this paper divided sihe coal mine into two regions according to gas content, consistent coefficient. Confirm the critical value of desorption index for drill cuttings for one region by laboratory method. Get the result as 0.83 ml/ (min0.5·g) and 0.75 ml/(min0.5·g)Though this way, reduce the out burst work by 1/3,which account 9% of the whole outburst control, and shortened the cycle of confirming the critical value on field.The innovation of this paper is the first time tried use principal component analysis on screening coal and gas outburst prediction sensitivity indexes, and analysis the principle of confirming of the critical value of the desorption index for regions of big coal mine with complicated geological condition.