Overburden Migration and Failure Characteristics in Mining Shallow Buried Coal Seam with Thick Loose Layer

Table 3

Correlation parameter values of H-B criterion.

Lithology	GSI	D	mi	m	s (10^−4)	a
Aeolian sand	10	0.7	2	0.01	0.02	0.59
Coarse sandstone	33	0.7	19	0.48	0.61	0.52
Medium sandstone	35	0.7	15	0.41	0.83	0.52
Fine sandstone	40	0.7	12	0.44	1.70	0.51
Sandy mudstone	30	0.7	5	0.11	0.41	0.52
Coal seam	15	0.7	10	0.09	0.05	0.56