Media Focus | "V" -shaped Deep Valley Reveals a "Rainbow"! The main arch ring of the Wujiao Special Bridge on the Yipan Expressway was successfully joined together

On January 20th, the main arch ring of the Shangwujiao Special Bridge on the Yijin section of the Yichang-Panzhihua Expressway, constructed by the Bridge Company, was successfully joined together, marking the successful completion of the hoisting operation of the main structure of the bridge and laying a solid foundation for the all-out efforts to achieve the full completion and opening to traffic of the entire line in 2026.

The Shangwujiao Special Bridge is located in Jinsha Town, Leibo County, Liangshan Prefecture, adjacent to Leibo County, and is situated in the Daliangshan Mountains. The bridge is 2,440.91 meters in total length. The main bridge is a 332.5-meter middle-supported concreteum-filled steel tube arch bridge, and the total steel structure of the entire bridge weighs 5,912 tons. This bridge is located in a complex mountainous area with "three highs" (i.e., high altitude, high wind force, and high seismic intensity). The terrain within the bridge area is sharply cut, belonging to a strong earthquake zone, with the basic seismic intensity reaching degree VIII. Moreover, it faces adverse geological conditions such as steep slopes, dangerous rock masses, and karst caves. The surrounding geological structure is extremely complex, the route layout is extremely difficult, the construction conditions are extremely arduous, the technical requirements are extremely high, the ecological environment is extremely fragile, and environmental protection and water conservation are extremely sensitive. During the construction process, two firsts in the history of domestic construction were set.

Facing a "V" -shaped canyon with a height difference of tens of meters between the two banks, a slope of 45 degrees and a depth of 210 meters, the construction team innovatively adopted an asymmetrical high and low main arch design, which was the first of its kind in the domestic construction history. This application not only ensured the stability of the bridge but also significantly reduced the excavation volume of the arch seat and the structural engineering volume, shortening the construction period by three months. The project cost is saved by 25 million yuan compared with traditional construction. To address the difficulties such as the inability to use water transportation for mid-span lifting on site and the design of the cable tower on Jinyang Bank to be moved backward, the construction team proposed to use the inclined rail transportation system to directly transport the arch ring from the prefabrication plant to the bottom of the cable hoisting system for lifting. They successfully set up a large-tonnage inclined rail transportation hoisting system (with a designed load capacity of 110 tons), and successfully lifted the side span of the arch ring weighing 83 tons. This hoisting construction method has avoided the environmental damage caused by large-scale excavation and effectively reduced the construction cost. It is also the first of its kind in China. Meanwhile, due to the dense population and winding and narrow access roads in the project site, the transportation of large profiles was difficult. The construction team innovatively designed a 6,000-square-meter fully prefabricated steel platform (approximately the size of 20 standard basketball courts), which enabled on-site processing of large profiles and effectively solved the transportation problem. At present, this project has successfully applied for two provincial-level construction methods, namely "Construction Method for Rapid Erection of Standardized Fully Assembled Steel Platforms under Complex Terrain Conditions" and "Construction Method for Transportation of Large-sized Heavy Components on Inclined Rails in Mountainous Steep Slope Terrain", providing good reference experience for the construction of similar Bridges.

After the completion of the Shangwujiao Special Bridge, it will become the only way for Leibo County to access the expressway network, opening up the "fast lane" for Leibo to enter high-quality development and injecting transportation impetus into rural revitalization.

Extended Reading

The Yichang-Panzhihua Expressway is currently the expressway project with the largest single investment scale in the history of domestic expressway construction, the longest construction mileage within Sichuan Province, and the greatest construction difficulty. It is a major project of the national strategy "The Belt and Road Initiative", a significant support project for the "Yangtze River Economic Belt", and also an important exit passage from Chengdu to the Panxi Economic Zone, connecting South Asia, and reaching the sea through rivers. Meanwhile, the completion of the project is of great significance for promoting the comprehensive rural revitalization of the Wumeng Mountainous Area and the Yi areas of the Greater and Lesser Liangshan Mountains, and achieving the coordinated economic development and regional cooperation of the five southwestern provinces of China.