On June 22, the world's largest diameter slurry shield machine "Shanhe" successfully crossed beneath the Yellow River's southern embankment, marking completion of the river crossing phase for the Huanggang Road Cross-Yellow River Tunnel Project in Jinan City, constructed by CRCC. This represents a major breakthrough in overcoming the project's most challenging section, characterized by the strictest control requirements, longest-duration risks, and most variable water and soil pressures.

The Huanggang Road Cross-Yellow River Tunnel Project serves as a flagship project supporting Jinan's implementation of China's national strategy for "Ecological Protection and High-Quality Development of the Yellow River Basin." Stretching approximately 5,755 meters from Lanxiang Middle Road in the south to the G309 interchange in the north, the tunnel features a 3,290-meter shield section with a single-bore, double-deck design and 60 km/h operating speed. The route passes beneath the Yellow River and its protective embankments, reaching maximum depths of 49.2 meters below ground with water and soil pressures up to 6.3 bar, demanding precise settlement control throughout construction.

The project team developed the custom-built "Shanhe" tunneling machine specifically for this challenging environment. At 163 meters long and weighing 5,200 tons, with a maximum boring diameter of 17.5 meters, it ranks as the world's largest diameter slurry balance shield machine currently under construction. Engineers implemented targeted upgrades to handle the Yellow River basin's unique geological conditions, including enhanced cutterhead opening ratios and high-capacity central flushing systems to prevent mud buildup. Innovative processing techniques now handle nearly 600 cubic meters of waste slurry hourly—a 50% efficiency improvement—while reducing filter cake moisture content below 30%.

The "Shanhe" machine has now excavated 2,752 meters, representing 83.6% of the shield tunnel's total length, while maintaining millimeter-level precision in surface settlement control. Upon completion, the tunnel will enhance connectivity between Jinan's main urban area and Qibu District while supporting the ecological protection and high-quality development of the Yellow River Basin.