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

Table 1

Experimental intensity values of coal and rock samples.

Lithology	E (GPa)	μ	φ (°)	c (MPa)	σc (MPa)
Aeolian sand	12	0.30	10	0.01	11.6
Coarse sandstone	34	0.28	32	1.8	21.8
Medium sandstone	32	0.25	34	2.3	35.3
Fine sandstone	33	0.28	36	2.8	44.6
Sandy mudstone	20	0.30	32	2.0	26.8
Coal seam	15	0.35	36	1.2	10.5