Mining-Induced Redistribution of the Abnormal Stress under the Close Bearing Coal Pillar for Entry Design

Table 1

Geological and engineering conditions of the research object.

Lithology	Thickness (m)	Bulk modulus (GPa)	Shear modulus (GPa)	Friction (°)	Cohesion (MPa)	Tension (MPa)
Sandstone	12.30	14.88	10.25	38	5.0	4.0
Coal seam 3	0.70	5.56	2.27	16	2.0	0.5
Mudstone	9.00	0.58	0.27	36	4.4	1.45
Coal seam 4	1.70	2.78	1.14	16	0.3	0.2
Sandy mudstone	3.25	8.33	4.76	35	3.5	0.65
Coal seam 5	2.76	5.56	2.27	9.5	1.6	0.5
Sandy mudstone	4.80	8.33	4.76	36	6.75	1.4
Sandstone	2.40	14.88	10.25	38	7.0	5.0
Mudstone	6.60	6.67	3.08	36	4.4	1.45
Limestone	4.50	23.02	11.24	42	10.0	8.0