Staggered-Supported Steel Anchor Box System for Cable-Stayed Bridges

This paper presents a novel anchorage structure for stay cables to reduce the load on the concrete pylon. Called the staggered-supported steel anchor box (SS-SAB), this anchorage structure provides self-balancing of the horizontal component of the cable tension force during cable tensioning; the vertical load is transferred to the concrete pylon through a staggered support. The SS-SAB can tolerate the forces within the spatial cable plane and reduce the cracking risks of the concrete pylon. To investigate the behavior of the SS-SAB, a half-scale specimen was designed and tested. Data on the deformation, crack patterns, local strains, and slippages were obtained that demonstrate that the SS-SAB can delay crack occurrences in the concrete pylon. In a supplementary analysis, a finite-element analysis performed using the ABAQUS software suite delivered good accuracy. From the test and numerical analysis, the influence of the cable angle on load sharing within the concrete pylon was investigated. The effective scope of applications of the SS-SAB is provided.