Arch first and beam later: Arch-rib integral installation construction technology for large-span tied-arch bridge

Tied-arch bridges are usually constructed using the beam first and arch later method, which enjoys the advantages of a short construction period and ease with which quality control can be achieved. However, when tied-arch bridges are constructed over roads or navigation channels, the construction will inevitably interrupt traffic, preventing the beam first and arch later construction from being realized. Therefore, this study investigates the arch-rib integral installation for the arch first and beam later method. The advantages and disadvantages of the conventional cable and arch-rib hoisting method are analyzed; further, this paper proposes the assembly of the arch rib on one side of the bridge, and the installation of the arch rib using a floating crane in a single step. Owing to the decreased cost, time saving, and ease of quality control, the horizontal installation method was preferentially adopted during arch-rib integral installation. Concreting at the arched beam area of the tie bar was conducted using Berea pieces assembled on a sling hanging basket, which can be repeatedly used to reduce the construction cost. Results obtained show that the arch first and beam later construction method is feasible.