Analysis of the Occurrence Mechanism for Coal and Gas Outburst Based on Multiple Discriminant Indices

Table 1

Lithology and thickness of the roof and floor of Panel 31020.

Name	Lithology	Feature description	Thickness
Main roof	Fine sandstone	Gray fine sandstone with a small number of patches at the top, sandy mudstone, mica sheets, and strips at the middle and lower parts	10.9 m
Immediate roof	Sandy mudstone	Gray-black sandy mudstone, dense, mica-bearing fragments	4.01 m
Immediate floor	Mudstone	Gray mudstone	0.3 m
Main floor	Sandy mudstone	Gray sandy mudstone, massive	1.5 m∼12 m