Experimental Study on Anchoring Behavior of Non-Persistent Jointed Rock Mass.

The jointed rock mass is a multi-crack body, which is cut by discontinuities such as joints and faults. These joints and faults destroy the integrity and continuity of rock mass and reduce the mechanical behavior of rock mass. The rock bolting is a suitable way to reinforce the jointed rock mass. By transferring tension and shear force, the rock bolting can make best use of the strength and stability of rock mass and restrict the deformation of rock mass. In this study, the specimens containing pre-set non-persistent joints were made with granite as prototype. A series of uniaxial compression tests of the reinforced jointed specimens were conducted by rock bolts with various inclinations. The relationships among the stress-strain, anchoring force, bolt strain, bolt inclination were studied, and the change rules of the parameters of the specimens and bolt with crack evolution during compression were analyzed. Results show that the peak strength and the equivalent elastic modulus of the anchored specimens with multiple non-persistent joints first increase and then decrease with the bolt inclination increasing. The optimal anchorage angle is about 65°. The anchoring force is relatively large when the angle between the rock bolt and the minimum principal stress surface is small. There is a strong internal correlation among the stress, anchoring force, bolt strain and crack evolution of the jointed specimens. The obtained conclusions in this study can provide a reference to the similar engineering practice. [ABSTRACT FROM AUTHOR]