Effect of Crack Propagation on Mining-Induced Delayer Water Inrush Hazard of Hidden Fault

Table 1

Geological and geomechanical properties of rock strata and hidden fault.

Lithology	Young’s modulus (GPa)	Tensile strength (MPa)	Poisson’s ratio	Density (kg•m^-3)	Friction angle (°)	Cohesion (MPa)	Porosity
Coarse-grained sandstone	28	4.5	0.27	2800	30	3.4	0.15
Fine sandstone	22	3.7	0.23	2550	28	2.0	0.13
Medium-grained sandstone	22	3	0.22	2700	28	2.0	0.13
Mudstone	18	2.6	0.28	2650	34	2.4	0.11
Coal seam 3	10	2	0.30	2500	29	1.4	0.12
Mudstone	18	2.6	0.28	2400	34	2.4	0.13
Siltstone	24	3.4	0.23	2500	26	2.8	0.1
Sandstone	22	3.1	0.26	2650	30	2.8	0.15
Coarse-grained sandstone	28	2.5	0.22	2700	28	2.5	0.12
Limestone	24	2.8	0.21	2650	32	2.8	0.13
Aquifer	25	6	0.27	2400	30	7	0.25
Fault	12	1.2	0.29	1900	20	1.65	0.11