Numerical Study on Soft Coal Pillar Stability in an Island Longwall Panel

Table 2

The mechanical parameters of the surrounding rock.

Lithology	Thickness (m)	Bulk K (GPa)	Shear G (GPa)	Internal friction angle f (°)	Cohesion C (MPa)	Tensile strength t (MPa)
Medium sandstone	6.05	25.2	15.0	30	3.0	1.5
Fine sandstone	4.24	20.2	10.0	35	2.4	4.13
Mudstone	3.16	6.2	4.0	22	0.6	0.15
# 7 coal seam	2.5	2.0	0.75	33	0.6	0.2
Shaly sandstone	1.3	7.0	5.0	24	1.0	1.0
Siltstone	6.73	12.3	9.0	30	1.2	1.5
Fine sandstone	7.97	20.2	10.0	35	2.4	4.13
# 8 coal seam	2.4	3.57	0.71	25	0.56	0.49
Carbonaceous mudstone	4.96	6.2	4.0	30	0.8	0.15
Siltstone	2.92	12.3	9.0	40	2.4	1.51
Medium sandstone	3.5	25.2	15.0	30	3	1.5