China News Service, Wenzhou, July 31 (Reporter Zhang Xu) Recently, the first main girder of the Oujiang Beikou Bridge in Wenzhou, Zhejiang was successfully erected.

  Wenzhou Oujiang Northkou Bridge is scheduled to be completed by the end of 2021.

After the bridge is officially opened to traffic, the Ningbo-Dongguan Expressway with a total length of about 645 kilometers will be fully completed. It will take more than one hour from the past more than one hour to only 15 minutes to cross the river from Yueqing, Wenzhou to Longwan, Wenzhou.

The construction site of Oujiang Beikou Bridge.

Photo by Chinanews reporter Zhang Xu

  Wenzhou Oujiang Beikou Bridge is the world's first three-tower four-span double-layer steel truss suspension bridge. The upper layer is the Ningbo-Dongguan Expressway and the lower layer is the G228 national highway.

The total length of the bridge is 7.9 kilometers, of which the main bridge spanning the Ou River is 2090 meters long. It is currently one of the most technically difficult and most complex bridges in my country and the world.

  "The first main girder is 28.5 meters long, 41.8 meters wide, and 12.5 meters high. It is more than 890 kilometers'crossing the ocean' and transported from Jiangsu Nantong to the bridge location of the Oujiang Beikou Bridge in Wenzhou, Zhejiang for hoisting construction." Wenzhou Transportation Development Group Zheng Fengli, deputy general manager and chief engineer, told reporters.

  According to reports, the construction process of the main beam of the project is complicated. The 2km hoisting range is divided into 9 construction areas, involving 9 different construction techniques such as swaying, positive hoisting, and cable hoisting. It is especially the first time that the mid-span is affected by aviation height restrictions. The designed cable-beam intersecting section adopts the relay hoisting technology of straddle cable hoist + positive hoisting, which is the first in China.

  In addition to the heavy shipping in the bridge site area, there are 110 beam sections that need to be intensively installed. The difficulty of construction, the huge working conditions, and the high complexity of the process are unprecedented in China.

  Pan Ji, general manager of Wenzhou Oujiangkou Bridge Company, introduced: "The maximum section weight of the main girder reaches 813 tons, and the existing domestic cable cranes cannot meet the lifting needs of a single unit." To solve this problem, the project developed the first domestic set of 1,000 tons. Grade cable crane, equipped with man-machine interface, sensor technology, communication technology and other technologies, to control the installation accuracy error within 5 mm, to ensure the safety and efficiency of the construction process.

Pan Ji, general manager of Wenzhou Oujiangkou Bridge Company, introduced the situation.

Photo by Chinanews reporter Zhang Xu

  As the first batch of green highway demonstration projects by the Ministry of Transport, Oujiang Beikou Bridge incorporates the green concept of "resource conservation, ecological environment protection, and social recognition" into the construction of the bridge.

  The project adopts the collinear design of the double deck system. The main bridge is a double deck steel truss girder structure, which realizes the intensive development of corridors and shoreline resources and saves about 193 acres of land.

  "Compared with concrete bridges, steel structure has the advantages of light weight, uniform materials, stable quality, factory-style manufacturing, assembly construction, high recycling and utilization, and it is more energy-saving and environmentally friendly." Zheng Fengli introduced, Oujiang Beikou Bridge vigorously promotes steel In structural application, the steel consumption of the whole bridge reaches more than 300,000 tons, and the main girder is an all-steel structure, which effectively improves the construction quality of the bridge. (Finish)