ADVANCE OF FRP ANCHOR BOLTS IN GEOTECHNICAL ANCHORING

Recently, fibre reinforced polymer(FRP)materials are gaining increasing popularity in the field of geotechnical anchoring owing to their superior characteristics such as the resistance to corrosion, high strength-to-weight ratio to conventional steel materials. FRP represents the future development direction of geotechnical anchorage material, but now its research results are relatively scattered. Based on the mechanical properties of the material, FRP has many advantages such as high tensile strength, long-term performance and good fatigue properties. However, there are several drawbacks for FRP to be considered in the anchorage design of rock and soil. They include poor bending and shear strength, as well as brittle failure. The failure modes of FRP anchorage system are summarized, which shows that the failure of anchorage system is usually caused by coupling effect of multiple failure modes. The key issues for the study of grouted FRP anchoring are summarized and include the influence factors of bond behavior between bolt and anchorage medium, calculation model for bond stresses, the bond-slip relationship and description of the stress distribution of the anchoring interface. Finally, this paper gives some examples in engineering application of FRP bolt at home and abroad, and also points out its further research direction.