Project description: In response to safety hazards caused by newly installed arch rib segments in cantilever state during the construction of multi-span continuous arch bridges, and issues such as frequent lateral movement of cable-stayed systems, unbalanced hanging of arch rib segments on middle piers, and increased cable tension on previous segments due to the hanging of subsequent arch rib segments, affecting the arch shape, this project proposes a method for fast and safe construction and intelligent monitoring and control of continuous arch bridges. This method can significantly shorten the construction period, save more than half of the cable usage, and improve safety, thus having important practical value for the fast and safe construction of continuous arch bridges.
Innovation one: To address the problem of frequent lateral movement of the cable lifting system during the construction of an arch bridge, a method of single-arch rib construction is proposed. Specifically, the left and right single-arch ribs are independently constructed. The single-arch diagonal tension is used to hang the arch rib until it is closed, and then the same method is used to hang the other arch rib until it is closed. Afterwards, the transverse braces are installed to form a dual-arch rib overall stress state, which can then proceed to subsequent processes such as pouring concrete. Single-arch rib construction can reduce the lateral movement of the cable lifting system to 1/n of the original, where n is the number of arch rib segments in a single half-span of the arch bridge. The clamp can be reused when installing the other arch rib, and the total amount of clamps used can be reduced by more than half due to a more reasonable stress distribution.
Innovation two: In response to the asymmetry and imbalance issues of the segments on the left and right sides of the middle pier during the construction of double-span or multi-span continuous arch bridges, a smart control method based on BeiDou satellite monitoring is proposed to balance the unbalanced forces at the middle pier. When installing a new segment, the tensioning of the locking cables is carried out immediately, and the intelligent control cable is used to ensure that the pier and the locking tower are in a balanced state. The construction method of using smart control cables to balance the middle pier ensures that the new segment is no longer in a cantilevered state, the flange is subjected to less force, and the change in locking cable tension is also small.
The intelligent control cable method proposed in this project for balancing the uneven forces on the pier during the construction of continuous arch bridges can be applied to the construction of continuous arch bridges spanning rivers and seas. The single-rib construction method can also be applied to the construction of single-span arch bridges, and it has good economic and social benefits. The intelligent control cable method for balancing the uneven forces on the pier can be applied to the construction of all continuous arch bridges, and the single-rib construction method is expected to be widely promoted for arch bridges with a span of up to 250m.
Organization: Guangxi University
Project Leader: Professor An Yonghui, et al.
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