Application and Principle of Bolt-Mesh-Cable Control Technology in Extremely Soft Coal Seam Roadway

Table 1

Physical and mechanical parameters of coal and rock mass in the model.

Lithologic characters	Density(kg·m^-3)	Volume modulus (GPa)	Shear modulus (GPa)	Angle of internal friction (°)	Cohesion (MPa)	Tensile strength (MPa)
Medium-grained sandstone	2500	10.2	7.0	30	6.6	1.9
Fine-grained sandstone	2600	39.3	28.3	35	11.4	5.8
Sandy mudstone	2530	1.3	0.7	29	5.5	2.8
No. 2-1 coal	1420	2.1	0.5	20	0.8	0.15
Mudstone	2520	2.7	1.6	28	5.1	2.6
Sandy mudstone	2580	45.3	31.2	33	9.7	5.2
Sandstone	2510	2.5	1.6	27	4.5	2.5