On August 28, the 'Wangjing No. 1,' the first domestically produced large-diameter slurry shield machine for high-speed railways with fully independent intellectual property rights, jointly developed by CRCC Heavy Industry and China Railway 14th Bureau Group, successfully crossed the Beijing 'Wangjing Tunnel Project' of the Beijing-Shenyang High-Speed Railway. This marks the completion of the main works of Beijing's first and also China's longest urban high-speed railway shield tunnel.
The Wangjing Tunnel is the only large-diameter shield tunnel on the entire Beijing-Shenyang High-Speed Railway line, with a total length of 8,000 meters. The shield-driven section at the tunnel exit is 3,168 meters long, and four shield machines were used to bore a single-tube, single-track tunnel from Shenyang toward Beijing. According to reports, during construction the tunnel faced geological challenges and safety risks such as large cross-sections and long distances. As the shield machine advances, it must cross beneath risk sources including the Capital Airport Expressway, the Airport Express Rail, Maquanying Station on Metro Line 15, the Red Brick Art Center, a sewage treatment plant, high-voltage towers, and multiple residential areas and tall buildings, with high settlement requirements and major safety risks. In addition, the deepest point of the tunnel is 43 meters, only 0.6 meters from the station retaining structure, over a crossing distance of 120 meters.
Tailor-made for the above geological characteristics and technical difficulties, the large-diameter slurry shield machine 'Wangjing No. 1' has an excavation diameter of 10.87 meters. It adopts the world's most advanced technologies such as indirect dual-chamber air-cushion dual-circuit control, transforming high-intensity, high-risk, and highly polluting tunnel boring operations into a relatively safe and efficient green construction mode to meet the requirements of fast, high-quality, efficient, safe, environmentally friendly, and highly integrated tunnel construction. The successful crossing by the shield machine overcame the most difficult point in the construction of the Beijing-Shenyang High-Speed Railway and achieved the highest domestic level of long-distance underpassing of an existing metro station.