A novel early-warning method for atypical outbursts disasters in mines: extraction of indexes from gas concentration data for the early warning of atypical outbursts

Accurate identification and forecasting of typical outbursts in mines remain scientific problems needed to be tackled. Based on the related data of the occurrence of atypical outbursts, this study employed theoretical analysis, laboratory test, mathematical treatment, and commercial test for investigating the physical and mechanical properties of coal that resulted in an atypical outburst, the quantitative conditions of the occurrence of atypical outbursts and the extraction of indexes from gas concentration data for early warning. Results show that the physical and mechanical properties of the coal rock where an outburst occurred fell in between the properties of the coal rock resulting in a rock burst and the properties of the coal rock resulting in coal and gas outburst, and an atypical outburst was easily triggered under high crustal and high gas pressure environment; gas extraction leads to the enhancement of coal rock mass brittleness and bump proneness. Based on specific physical and mechanical characteristics of the coal that results in an atypical outburst, the related early-warning information in gas concentration data that can reflect the evolution process of atypical outburst disasters were mathematically extracted, and the mathematical model of early-warning indexes was established.