Full Internal Force Inversion Method for Ground Rock Bolts in Transmission Cableways Based on FBG Curvature Field Reconstruction

With the rapid advancement of ultra-high voltage (UHV) transmission projects in China's topographically complex regions, freight cableways have been widely adopted for material transportation during power line construction due to their efficiency and environmental benefits. To ensure cableway safety and enhance the reliability and monitoring accuracy of anchoring systems, this paper proposes a full internal force inversion method for rock bolts based on fiber Bragg grating (FBG) discrete curvature field continuous reconstruction, applied to monitor the mechanical states of cableway load-bearing rock bolts in transmission engineering. Traditional rock bolts monitoring methods suffer from limitations such as sparse measurement points, weak anti-interference capability, and poor real-time performance, making them unsuitable for the complex construction environments of UHV transmission lines. To address these challenges, this study designs a tri-directional symmetric FBG array configuration and integrates it with a Lagrange curvature continuous inversion algorithm to achieve high-precision, synchronized dynamic inversion of axial force, bending moment, and shear force in anchor rods. Experimental results demonstrate that the proposed method exhibits excellent real-time performance, accuracy, and stability, providing a reliable monitoring solution for anchoring safety in power line material transportation systems, with broad application prospects in UHV transmission engineering.