Dynamic Changes in Surface Damage Induced by High-Intensity Mining of Shallow, Thick Coal Seams in Gully Areas

Table 3

Physical and mechanical parameters of the rock formations.

Serial number	Lithology	Volume weight (kg·m^−3)	Bulk modulus (GPa)	Poisson’s ratio	Compressive strength (MPa)	Tensile strength (MPa)	Cohesion (MPa)	Internal friction angle (°)
1	Sandy loess	2270	0.01	0.24	0.16	0.03	0.01	13
2	Sandy clay	2360	2.3	0.22	13	1.7	1.5	38
3	Fine sandstone	2500	4.2	0.30	23	1.6	2.1	45
4	Sandy mudstone	2650	2.7	0.26	17	1.2	1.2	36
5	Coarse sandstone	2560	3.8	0.19	20	1.9	2.1	45
6	Sandstone	2500	4.3	0.25	27	2.0	2.8	43
7	Fine sandstone	2550	4.2	0.30	23	2.1	2.1	45
8	Sandy mudstone	2600	2.2	0.23	15	1.4	1.7	33
9	Coal Seam no. 5	1400	1.2	0.35	15	1.3	1.1	29
10	Mudstone	2500	2.9	0.21	18	1.7	1.4	31
11	Siltstone	2600	3.6	0.26	21	2.1	2.2	40
12	Sandy mudstone	2600	2.2	0.23	15	1.7	1.3	33
13	Coal Seam no. 6	1380	1.4	0.33	20	1.4	1.4	33
14	Sandy mudstone	2650	2.7	0.28	17	1.6	1.5	36