The Study on Large-Diameter Drilling Prevention Method of Rock Burst in the Xinxing Coal

Table 6

Physical and mechanical parameters of coal.

Lithology	Density/kg/m^3	One-way tensile strength/MPa	Bulk modulus/GPa	Shear modulus/GPa	Cohesion/MPa	Internal friction angle/°
Loading medium coarse sandstone	2707	108.88	18.17	12.07	14.5	37
Direct top siltstone	2270	97.07	10.8	10.01	10.7	40
Pseudo top fine sandstone	2180	78.05	5.17	7.14	7.2	28
Coal	1370	18.35	2.46	1.77	2.7	25
Direct bottom fine sandstone	2180	98.05	5.17	7.14	7.2	30
Old siltstone	2440	94.25	12.8	10.01	10.7	40