On October 22, the super-large-diameter slurry balance shield machine China Railway 1659, jointly developed by China Railway No.4 Engineering Group, China Railway Tunnel Group and China Railway Engineering Equipment Group, completed final assembly and rolled off the production line. It will be used for Lot 1 of the Hefei G4001 Link Project (West Extension of North Second Ring Road). This marks a key technological breakthrough for China's super-large-diameter slurry shield equipment under complex working conditions including hard rock, fractured zones, underwater sections, sharp-radius turning and steep slopes.

The shield-driven section of the project stretches approximately 2.9 kilometers. The tunnel adopts a twin-bore double-deck structure. Construction teams need to tackle a host of challenges, including long-distance hard rock tunneling amid highly complicated geological conditions and undercrossing the Dongpu Reservoir Drinking Water Source Protection Zone.

China Railway 1659 boasts an excavation diameter of 16.68 meters and an overall length of 125 meters, comparable to a five-and-a-half-story building. With a maximum thrust of 28,149 tons and a total weight of around 4,800 tons, it represents the top-tier specification among its counterparts in China at present.

The West Extension Project of North Second Ring Road is a key transport project of Hefei and a vital east-west artery of the city's “five horizontal and seven vertical” expressway network framework.

Upon completion, the project will shore up weak links in the road network of the main urban area, strongly underpin Hefei's strategy of boosting urban development through science and innovation as well as the construction of a modern, international and innovative city, and facilitate the development of the Hefei National Comprehensive Science Center and a source of technological innovation.

Source: Anhuinews.com