The use of fiber-reinforced polymer (FRP)-reinforced concrete (RC) soft-eyes in tunnel constructions has been gaining noticeable popularity as a successful and practical application of the non-corrosive FRP reinforcement. This unique use of FRP bars takes advantage of their anisotropic property, meaning they are strong along the main axis but can be machined, abraded away, or consumed by tunnel boring machines (TBMs). Consequently, the research program herein offers an inclusive experimental database followed by a detailed theoretical analysis and design provisions for FRP-RC soft-eyes subjected to either axial, flexural, combined axial and flexural loads, or shear stresses. The experimental evidence from our study accentuated the feasibility of FRP reinforcement to maintain strength and stability of FRP-RC elements against all various applied loads. In addition, this paper provides a summary of three field applications of FRP-RC soft-eyes in tunnel constructions located in Canada, highlighting the details of FRP reinforcement, material characteristics, project location, design considerations, and construction methods. The significant field experience herein demonstrated that no major problems or any unanticipated performance-associated troubles were monitored during the construction and service phases. |
