Study of Shear Capacity of Jointed Rock Mass with Prestressed Anchor Bolt

Table 2

Initial shear strength in shear test under different anchorage conditions.

Shear strength of the jointed surface at the initial shear stage (kN)
Normal stress (MPa)	Anchoring bolting + prestress (2.5 kN)	Anchoring bolting + one end fixed and another end free	No anchoring bolting
0.70	42.80	41.98	39.00
0.35	25.95	21.71	18.95
0.20	17.12	15.11	12.42

Shear strength at the initial shear stage is the shear strength corresponding to the turning point in the shear curve in Figure 5. The force of 2.5 kN is the prestress applied when the anchor rope is locked. In other words, the force of 2.5 kN is the prestress of anchor cable before the normal stress is applied to the rock mass.