Design of Longwall Coal Pillar for the Prevention of Water Inrush from the Seam Floor with Through Fault

Table 2

Physical and mechanical parameters of part of rock in the 23503 working face.

Rock stratum	Thickness (m)	Elastic modulus (MPa)	Tensile strength (MPa)	Friction angle (°)	Poisson ratio	Volumetric weight (kg·m^-3)
Siltstone	7	8800	4.5	26	0.24	2500
Medium sandstone	10	8500	2.9	28	0.26	2450
Sandy mudstone	1	2850	0.7	32	0.33	2200
No. 5 coal	4	1650	0.8	36	0.32	1500
Siltstone	1	8650	4.3	26	0.25	2460
Quartz sandstone	3	8850	4.8	25	0.24	2650
Sandy mudstone	1	3500	0.7	33	0.34	2250
Siltstone	6	8600	3.3	28	0.24	2530
Quartz sandstone	12	8850	3.7	26	0.25	2650
Siltstone	1	8750	3.9	27	0.24	2550
Quartz sandstone	3	8850	3.7	26	0.25	2650
No. 10 coal	3	2000	0.8	38	0.33	1520
Sandy mudstone	1	2870	0.8	32	0.34	2200
Aluminous mudstone	9	2800	0.7	35	0.35	2050
Ordovician limestone	12	10000	8.0	30	0.26	2600