Study on Deformation–Failure Behavior and Bearing Mechanism of Tunnel-Type Anchorage for Suspension Bridges Based on Physical Model Tests

This study aims to investigate the mechanical behavior and failure mechanisms of tunnel-type anchorages for suspension bridges under complex geological conditions, using the Wujiagang Yangtze River Bridge as a case study. A scaled physical model (1:40) was employed to systematically examine deformation patterns, stress transfer, and ultimate bearing capacity under incremental loading. Key results demonstrate a quasi-symmetrical “double-hump” deformation response under service load, with axial stress concentrated at the rear anchorage face. The critical safety threshold was identified at 9 times the design load (9P), beyond which plastic damage initiates. Uplift resistance was found to rely primarily on rear rock mass confinement, while sandstone interlayers and mortar joints showed negligible impacts on stability. These findings provide practical criteria for the design and safety assessment of tunnel anchorages in rock-dominated environments.