On June 2, with the smooth pouring of the final batch of concrete, the south bank main tower of the G3 Tongling Yangtze River Road-Rail Bridge, surveyed and designed by China Railway Major Bridge Reconnaissance & Design Institute and constructed by China Railway Major Bridge Engineering Group, was successfully capped.

The G3 Tongling Yangtze River Road-Rail Bridge is located in the suburbs of Tongling City, Anhui Province. The project connects the Tongling urban area on the south bank of the Yangtze River with Zongyang County on the north bank, and is an important project for Tongling to improve its comprehensive transportation infrastructure and achieve cross-river development. The project has a total length of 11.88 kilometers, with a combined road-rail section of 2.682 kilometers, featuring three river-crossing functions: expressway, intercity railway, and freight railway. The main river-crossing bridge is 1,505 meters long with a main span of 988 meters, and is the world's first steel truss girder bridge with a cable-stayed suspension cooperative system.

The bridge features "large span, heavy load, and new structure." Facing the difficulty of being a "world first," the team led by Xiao Haizhu, chief engineer of China Railway Major Bridge Reconnaissance & Design Institute, made tremendous efforts in the preliminary design stage of the project to ensure that every link, every structure, and every design was as perfect as possible. The main tower of the bridge bears forces characteristic of both cable-stayed and suspension bridges, making the force conditions relatively complex, and Xiao Haizhu's team carried out targeted designs.

Detailed calculations and analyses were conducted on the forces acting on the main tower at different stages and under different working conditions, and a reasonable pentagonal cross-section was selected, taking into account both force requirements and aesthetic needs.

The cable-stayed anchorage zone of the main tower adopts a steel anchor beam structure, making the forces on the main tower clearer and construction more convenient.

The upper crossbeam innovatively adopts an open trough-shaped cross-section without a bottom plate. Compared with traditional box-shaped crossbeams, while meeting force requirements, it avoids interference with the anchorage layout of the top cable-stayed cables caused by horizontal diaphragms inside the tower column, effectively reducing construction difficulty and saving construction time.

"Since the construction of the G3 Tongling Yangtze River Road-Rail Bridge started on January 4, 2022, the project has progressed rapidly. The successful capping of the main tower has laid a solid foundation for the project to enter the cantilever assembly construction of the main girder next," introduced Qiu Feng, the project manager. The main tower construction adopted a 9-meter fully automatic intelligent hydraulic climbing formwork. Compared with traditional 6-meter segment construction, this method reduces 12 construction cycles and can save about 120 days of construction time under the same formwork-curing conditions. The 9-meter climbing formwork method used for the G3 Tongling Yangtze River Road-Rail Bridge is a world first and a major breakthrough in the field of bridge construction.