Investigation on the Movement and Fracture Characteristics of an Extra-Thick Hard Roof during Longwall Panel Extraction in the Yima Mining Area, China

Table 5

Physical and mechanical parameters of rock strata in the FLAC^3D model.

Rock strata	Thickness (m)	Density (kg·m^−3)	Bulk modulus (GPa)	Shear modulus (GPa)	Cohesion (MPa)	Friction angle (°)	Tensile strength (MPa)
Conglomerate	39	2 950	20.94	18.03	12.21	41	10.63
Fine sandstone	2	2 900	9.27	8.84	7.59	31	6.72
Conglomerate	3	2 950	20.94	18.03	12.21	41	10.63
Fine sandstone	2	2 900	9.27	8.84	7.59	31	6.72
Siltstone	2	2 734	12.95	10.12	9.06	30	8.74
Mudstone	2	2 486	6.17	5.54	4.52	22	4.34
Fine sandstone	1	2 900	9.27	8.84	7.59	31	6.72
Mudstone	24	2 486	6.17	5.54	4.52	22	4.34
Coal seam	5	1 440	4.67	4.47	4.40	26	4.06
Siltstone	10	2 734	12.95	10.12	9.06	30	8.74