Physical Simulation of the Water-Conducting Fracture Zone of Weak Roofs in Shallow Seam Mining Based on a Self-Designed Hydromechanical Coupling Experiment System

Table 1

Main physical and mechanical properties of rock strata.

Layer number	Lithology	Density (kg/m^3)	Compressive strength (MPa)	Poisson’s ratio	Modulus of elasticity (GPa)
1	Silt	1700	0.7	0.31	1.6
2	Gravel	2450	12.0	0.24	22.0
3	Mudstone	2300	9.5	0.30	7.6
4	Coarse sandstone	2410	23.2	0.27	17.8
5	Muddy siltstone	2350	19.6	0.26	14.8
6	Mudstone	2300	9.5	0.30	7.6
7	Middle sandstone	2450	26.0	0.25	22.4
8	Fine sandstone	2550	27.5	0.26	23.2
9	Mudstone	2300	9.5	0.30	7.6
10	Fine sandstone	2550	27.5	0.26	23.2
11	Mudstone	2300	9.5	0.30	7.6
12	Siltstone	2500	25.5	0.26	22.0
13	Carbonaceous mudstone	2250	8.4	0.29	6.8
14	21-1 coal	1400	6.8	0.28	3.2
15	Mudstone	2300	9.5	0.30	7.6