On August 21st, a significant milestone was reached on the Anhui section of the new Hefei-Wuhan High-Speed Railway, with the completion of the main steel truss structure for the Jinzhai Shihe River Grand Bridge. This crucial engineering feat marks a domestic first, as the bridge is the inaugural high-speed railway structure in China to feature a deck-type double-composite steel truss continuous beam design for trains operating at 350 km/h. The project provides essential practical experience for the future construction of high-speed rail bridges nationwide.
Located within the Jinzhai County Economic Development Zone in Lu'an City, the bridge spans 540 meters with a design incorporating a (72+132*3+72) meter deck-type double-composite continuous steel truss structure. Its central span of 132 meters crosses the Shihe River. The project is managed by Wangan Railway Anhui Company, designed by China Railway Design Group, and constructed by China Railway 11th Bureau. In a departure from traditional concrete continuous beam bridges, this structure uses an innovative steel-concrete composite design, effectively combining precast concrete panels with the steel truss. This integration leverages the complementary strengths of concrete's compressive capacity and steel's tensile strength, achieving a synergistic load-bearing efficiency greater than the sum of its parts. Weighing just approximately 13,000 tons, the design significantly reduces structural load while meeting the stringent rigidity and stability demands of 350 km/h high-speed rail operations.
Zhao Qian, a senior engineer at Wangan Railway Anhui Company, explained that to ensure structural integrity, the entire bridge is constructed with high-strength steel and employs all-welded connections. The primary load-bearing components adhere to full-penetration first-grade welding standards. Through cast-in-place concrete and shear stud force transmission mechanisms, the steel truss and bridge deck are firmly consolidated, forming an integrated stress system. The construction involved the careful assembly of 661 steel components using a combination of bracket support and dual-crawler crane symmetrical hoisting. This process strictly followed a sequence of starting from the pier tops, extending symmetrically, and performing staged closures for precise installation. To maintain quality, a third-party non-destructive testing system was introduced to strictly control the quality of all welded joints, achieving a 100% first-pass acceptance rate on critical nodes.
Addressing challenges like the bolt-free installation and lengthy high-altitude welds, the team collaborated with universities to develop a full-bridge alignment monitoring system. This enabled dynamic monitoring and real-time correction during construction, and the use of a factory-fabrication and on-site assembly model improved both efficiency and welding accuracy. A key technical highlight of the bridge is its use of the steel beam's inherent elastic rebound force in place of traditional prestressed steel cables. During construction, the steel beam was jacked up to a maximum of 85 centimeters to create a slight arch. After the concrete was poured and cured, the beam was lowered, and the rebound pressure generated pre-compression stress directly in the bridge deck, effectively preventing cracks. This technique simplifies the construction process and markedly enhances the bridge's durability.
Huang Guang, Chief Engineer of the China Railway 11th Bureau's HWR 3rd bid section, noted that thanks to these innovations, the bridge has reduced steel usage by 10% to 20%, while its structural rigidity is 20% to 40% higher than a pure steel structure. This results in better ride comfort and safety, setting an efficient, green, and economical engineering benchmark for high-speed rail steel truss bridges in China.
As a key component of the national "Eight Vertical and Eight Horizontal" high-speed rail network's Yangtze River corridor, the Hefei-Wuhan High-Speed Railway is the Hefei-Wuhan section of the Shanghai-Chongqing-Chengdu high-speed rail line, passing through Anhui and Hubei provinces. Once operational, it will create a new major high-speed rail link between Hefei and Wuhan. This will further optimize the railway network layout in the Yangtze River Economic Belt, improve travel convenience for residents along the route, and play a significant role in accelerating the development of an integrated transportation system along the Yangtze River, better serving regional coordinated development, and promoting the high-quality growth of the Yangtze River Economic Belt.