Study on Roof Presplitting Mechanism and Deformation Control of Reused Roadway in Compound Soft Rock by Roof Presplitting Approach

Table 1

Physical and mechanical parameters of rock stratum.

Parameters	Bulk (GPa)	Shear modulus (GPa)	Tension (MPa)	Cohesion (MPa)	Friction (°)	Density (kg·m^-3)
Sand mudstone	12	8.6	2.1	1.2	32	2600
5# coal seam	1.5	2.0	1.2	0.9	24	2450
Mudstone	4.3	8.6	1.7	1.4	30	2200
Fine sandstone	36	12.6	7.2	1.45	31.5	2600
Siltstone	25	4.6	3.6	1.0	33	2500
2# coal seam	1.5	2.0	1.2	0.9	24	2450