Catastrophe Mechanism of Stress-Fissure Coupling Field in Mining Close Distance Seams in Southwest China

Table 1

Physical and mechanical properties of rock mass.

No.	Lithology	Height (m)	Buried depth (m)	Density (kg/m^3)	Volume modulus (GPa)	Shearing modulus (GPa)	Internal friction angle (°)	Internal cohesion (MPa)	Tensile strength (MPa)
1	Limestone	180	183	2800	3.06	2.39	42	6.53	5.70
2	Marl	15	198	2750	2.27	1.56	38	4.43	3.53
3	Mudstone	12	210	2670	1.48	0.65	28	2.14	1.38
4	Limestone	30	240	2800	3.06	2.39	42	6.53	5.70
5	Siltstone	10	250	2840	1.94	0.90	33	2.65	2.10
6	Muddy siltstone	3	253	2770	2.50	1.16	35	3.15	2.31
7	Siltstone	5	258	2840	1.94	0.90	33	2.65	2.10
8	4# coal	4	262	1500	1.18	0.55	34	1.56	1.12
9	Muddy siltstone	6	268	2770	2.50	1.16	35	3.15	2.31
10	Mudstone	4	272	2670	1.48	0.65	28	2.14	1.38
11	Siltstone	3	275	2800	2.78	1.28	37	3.64	2.25
12	Siltstone	6	281	2840	1.94	0.90	33	2.65	2.10
13	Fine-grained sandstone	4	285	2800	2.78	1.28	37	3.64	2.25
14	Siltstone	6	291	2840	1.94	0.90	33	2.65	2.10
15	9# coal	3	294	1500	1.18	0.55	34	1.56	1.12
16	Siltstone	3	297	2840	1.94	0.90	33	2.65	2.10