Development of Modified Grouting Material and Its Application in Roadway Repair Engineering

Table 7

Rock mechanics parameters.

Rock stratum	Bulk modulus (GPa)	Shear modulus (GPa)	Internal friction angle (°)	Cohesion (MPa)	Tensile strength (MPa)
Overlying strata	9.80	8.00	34	5.50	2.10
Main roof	6.40	5.30	28	3.30	1.90
Immediate roof	4.50	4.90	27	3.10	1.70
9# coal seam	2.60	2.50	20	1.20	1.30
Immediate floor	4.80	4.80	28	2.90	1.68
Main floor	5.40	5.30	28	3.35	1.89
Underlying strata	9.70	8.32	33	5.40	2.06