Performance of a U-shaped anchoring system for cable-stayed bridges

An innovative U-shaped anchoring system was previously proposed to prevent the cracking of cable-pylon anchorage zones of concrete pylons in long-span cable-stayed bridges. The anchoring system transfers the cable force to the concrete pylon in the form of radial pressure, which fundamentally prevents the tension cracking of the concrete pylon column. In this study, the mechanical performance of the U-shaped anchorage system was investigated using finite element analysis. Subsequently, the fatigue performance of the steel strand in the U-shaped saddle, the anti-sliding performance of the U-shaped saddle, and the corrosion resistance of the steel strand were experimentally studied. The results of finite element analyses indicate that the U-shaped anchorage system significantly avoids concrete cracking in the cable anchorage zones provided that the strength grade of concrete filler is no less than C30. The experimental results show that the steel strand with polyurea coating has sufficient fatigue resistance as well as adequate anti-corrosion performance, and the anti-sliding performance of the anchoring system is sufficiently good. These critical studies validate the superiority of the U-shaped anchoring system with polyurea-coated steel strands, which should observe wide engineering applications in long-span cable-stayed bridges.