Analysis of the Critical Safety Thickness for Pretreatment of Mined-Out Areas Underlying the Final Slopes of Open-Pit Mines and the Effects of Treatment

Table 2

Physical and mechanical parameters of rock mass and soil.

Type of rock; mass and soil	Weight γ; /kN/m^3	Cohesion c; /kPa	Angle of internal friction φ; /°
Quaternary	18.7	27	25
Marble	26.5	90	31
Skarn	37.6	170	32
Granite	26.4	180	33
Filling	20.0	85	27