A Gas Seepage Modeling Study for Mitigating Gas Accumulation Risk in Upper Protective Coal Seam Mining Process

Table 1

Physical and mechanical parameters of the rock and coal.

Serial number	Lithology	Thickness (m)	Density (kg·m^−3)	Bulk modulus (GPa)	Shear modulus (GPa)	Cohesion (MPa)	Internal friction angle (°)	Strength of extension (MPa)
1	Fine sandstone	8.01	2500	3.0	1.5	2.0	35	1.5
2	Siltstone	2.99	2400	2.6	1.6	2.2	36	1.5
3	Coal line	0.49	1450	1.8	1.0	1.5	30	1.0
4	Siltstone	3.67	2500	2.6	1.6	2.2	36	1.5
5	Fine sandstone	4.23	2500	2.9	1.9	2.8	39	1.8
6	2# coal seam	1.00	1450	1.8	1.0	1.5	30	1.0
7	Sandy mudstone	2.58	2300	2.0	1.3	2.0	38	1.5
8	Siltstone	4.92	2400	2.6	1.6	2.2	36	1.5
9	Middle-fine sandstone	8.11	2600	4.0	2.4	2.8	38	2.8
10	Siltstone	1.98	2400	2.6	1.6	2.2	36	1.5
11	3# coal seam	6.09	1400	1.8	1	1.5	30	1.0
12	Sandy mudstone	2.97	2400	2.0	1.3	1.5	30	1.2
13	Fine sandstone	5.03	2500	2.8	1.8	2.9	36	1.7
14	Middle-fine sandstone	45.64	2500	3.0	1.5	2.0	35	1.5