Strata Caving and Gob Evolution Characteristic in Longwall Mining

Table 2

Contact properties in the BBM.

Discontinuity		Kn (GPa/m)	Ks (GPa/m)	C (MPa)	φ (°)	σt (MPa)
Fictitious contact	Siltstone	11.37	11.37	1.38	38.57	0.84
	Coal	4.39	4.39	0.36	34.45	0.23
	Clasolite	5.91	5.91	1.27	38.10	0.40
	Fine sandstone	35.57	35.57	2.48	35.89	2.03
	Mudstone	41.79	41.79	1.38	34.90	0.43
	Coal (mining)	20.89	20.89	1.38	34.90	0.43
	Mudstone	5.85	5.85	0.36	34.45	0.23
Joints		50	25	0	30.0	0