Internal Stress Distribution Monitoring for Prestressed Anchor Cables and Laboratory Test

This paper proposes an internal stress monitoring structure and stress distribution monitoring method for prestressed anchor cables, validated through experiments at three scales. Tensile breaking tests of a single monitoring structure confirmed its strength exceeds that of the steel strand, with consistent deformation up to the yield load, meeting basic requirements for axial force monitoring. Dual-structure repeated tensioning tests at various stress levels showed consistent deformation. After 10 cycles of 220 kN tensioning, pro-cessing stresses and residual strains were eliminated, enhancing accuracy. A linear calculation formula be-tween monitored strain and axial force is established using data from 40 post-elimination cycles. A 9-m graded tensioning test with 8 monitored structures under simulated conditions revealed gradual stabiliza-tion of prestress attenuation (≈6%) along the cable length as load increased. The monitoring structure ac-curately captured stable force measurements reflecting characteristic changes. These results validate the ra-tionality and feasibility of the proposed structure and method for practical applications.