Load Transfer Mechanism and Parameter Analysis of Anchor Box Type Cable-girder Anchorage for Long-span Cable-stayed Bridge with Deck Accommodating Both Highway and Railway Traffic

In response to the eomplex structural form and force of the anchor box-type cable-girder anchorage structure, in the case of the anchor box-type cable-girder anchorage structure of an under-construction four-tower large-cantilever cable-stayed bridge with deck accommodating both highway and railway traffic, numerical simulation was used to analyze the stress distribution law and load transfer mechanism under the design cable force, and the reasonable structural design parameters were studied through parameter analysis. The results show that different degrees of stress concentration exist in each stressed plate of the cable-girder anchoring structure of the bridge, and the stress concentration mainly occurs at the edge of the opening of the plate and the junction between the plates. The four connecting welds between the supporting plates and the beam webs transmit 92. 5% of the cable force in the form of shear force, with higher cable force transmission efficiency than that of the traditional steel anchor box. The changes in the thickness of the stressed plates in the anchorage structure have a coupling effect on the mechanical behavior of each plate. The force of the endplate and the support plate is most sensitive to the change of their thickness, and the increase of the thickness of the endplate and the support plate can alleviate the stress concentration of each plate, but the two outer stiffening plates have minor influence on the force of each plate of the anchorage structure. This paper proposes that this type of cable-beam anchorage structure should remove the stiffening plates on both sides based on retaining the original design of the endplate and the support plate, to have a better economy. © 2023 Science Press. All rights reserved.