Recently, as a 36.91-ton arch rib segment was slowly lifted into place, the steel pipe arch of the first 110-meter double-cable-plane single-arch-rib simply supported arch bridge on the Shanghai municipal railway of Nanhui Branch Line Section 4 was successfully closed.

The arch bridge erected this time is located over the Central River of the Ten-Thousand-Mu Farmland. It is a double-cable-plane single-arch-rib simply supported arch bridge constructed with cast-in-place concrete on falsework, with a length of 110 meters and a width of 17.8 meters. The arch rib adopts a transverse dumbbell-shaped truss section, and the height of the arch rib section varies from 3.2 meters at the arch springing to 2.4 meters at the crown. The suspenders are arranged in parallel double-suspender configuration, with a longitudinal spacing of 5.5 meters between suspension points, and a total of 17 pairs of suspenders are installed across the bridge. The girder is divided into 3 segments for staged casting, and the arch rib is divided into 9 segments.

During construction, challenges such as high docking precision and difficult high-altitude welding were encountered. In the closure stage of the arch bridge, to effectively control closure precision, a temporary closure locking followed by main pipe welding mode was adopted, controlling the docking error of the chord pipes at the closure opening to within 3 millimeters and achieving the goal of stress-free closure.

The maximum distance for the arch rib segment lifted this time was 28 meters, with a maximum lifting weight of 55.64 tons. To ensure lifting safety and precise positioning, the project team held multiple special meetings and conducted repeated demonstration and verification of working tools involved in the steel arch lifting, including wire ropes, lifting lugs, support jigs, and arch springing brackets, ensuring construction safety and quality and laying a solid foundation for the subsequent construction of the project.