Presplit Blasting Technique in Treating Hard Overlying Strata: From Numerical Simulation to Field Practice

Table 1

Key test results of rock samples.

Rock samples	UCS (MPa)	Tensile strength (MPa)	Elastic modulus (GPa)	Poisson’s ratio	Friction angle
Fine sandstone	95.0	9.5	35.1	0.2	30.0
Medium sandstone	72.0	7.5	25.0	0.2	31.0
Sandy mudstone	55.0	2.5	14.0	0.2	34.0
3# coal seam	14.5	2.0	4.3	0.4	31.0
Mudstone	30.0	2.2	12.2	0.2	29.0