Experimental Study on Shear Mechanical Properties of Rock Mass Structural Plane Anchored by GFRP/CFRP Hybrid Fiber

Aiming at the problems of poor corrosion resistance of traditional metal bolts and insufficient toughness or high cost of single FRP bolts, this study takes GFRP/CFRP hybrid fiber bolts as the research object, and conducts direct shear tests on anchored red sandstone structural plane specimens with different roughness under different normal stresses, so as to systematically analyze the shear deformation characteristics, strength, toughness and failure modes of the hybrid fiber anchoring system. The results show that the shear strength and total energy absorption of the anchored structural plane are much higher than those of the unanchored structural plane, and increase significantly with the increase of normal stress and structural plane roughness. Compared with single GFRP bolts, the peak strength of hybrid fiber bolts is increased by about 5% ~ 15%, and they have better ductility and residual strength. The failure mode is progressive damage with outer GFRP peeling and inner core CFRP bearing, which effectively avoids brittle shearing.