Abstract:Due to the prominent safety risks and significant impact on the existing traffic operations, the approval and design difficulty of bridges involving railway and aviation clearance is much higher than that of conventional bridges. Taking the super-large bridge at the north extension of Wuhan Metro Line 7 spanning the freight line of Beijing - Guangzhou Railway as the background, the control factors of long-span rail transit viaducts under the complex boundary conditions involving railway and aviation clearance at the same time are analyzed, and the schemes of bridge type are compared and selected. The key indicators of the rotatory base slab in the recommended scheme are checked and calculated to determine the reinforcement and section height of base slab. The finite element software is used to analyze the stress state of the pile foundation of rotatory base slab under different working conditions. It is found that its stress characteristics are different from those of the rigid base slab. Based on the derivation of mechanical formulas, the post-construction creep control measures for long-span continuous beam bridges are studied to effectively control the post-construction creep. The recommended bridge type scheme of this bridge has been successfully approved, and all indicators of the rotatory structure are normal in the rotating construction process. The creep deformation of the main girder after completion is basically consistent with the calculated values, which provides the reference experience for similar projects.
