en.Wedoany.com Reported - With the precise arrival of the "Zhengcheng" super-large diameter tunnel boring machine at the receiving position, the northern shield tunnel of the Jinan Aerospace Avenue Yellow River Tunnel project, constructed by the Tunnel Bureau under CCCC First Highway Engineering Group, has been successfully completed, marking the dual-tube breakthrough of the project. This tunnel is a core component of Jinan's "Four Bridges and Four Tunnels" strategic layout, with a main line length of 3,888 meters, adopting a two-way six-lane urban arterial road standard and a design speed of 60 km/h. Upon completion and opening to traffic, travel time between the north and south banks of the Yellow River will be reduced from the current detour of about 30 minutes to a direct 8-minute trip.

Located between Jinan High-tech Zone and the Start-up Area for New and Old Kinetic Energy Conversion, the Jinan Aerospace Avenue Yellow River Tunnel starts at the intersection of Aerospace Avenue and County Road X012, runs westward along the under-construction Aerospace Avenue, crosses beneath the Yellow River, and ends at the receiving shaft northwest of Madian Village on the west bank. The tunnel adopts a double-tube single-layer shield form, with an outer diameter of 14.5 meters and an inner diameter of 13.3 meters. The northern shield tunnel, which has now been completed, is 3,245 meters long and was excavated using the "Zhengcheng" super-large diameter slurry balance tunnel boring machine with a cutting diameter of 15.07 meters, advancing in a single direction. The "Zhengcheng" TBM has a total length of 179 meters and a total weight of 5,300 tons, equivalent to the height of a five-story building.

The Jinan section of the Yellow River is a typical "suspended river above ground," with the daily water level 4 to 5 meters above the urban surface and a flood control water level difference exceeding 10 meters. The tunnel site crosses the main channel of the Yellow River, the levees on both banks, and the siltation areas. The strata mainly consist of silty clay and fine silty sand, with local inclusions of calcareous nodules, featuring variable geology and extremely high water pressure. Since the start of tunneling, the project team has faced a series of technical challenges, including long-distance composite strata, high water pressure permeability, levee settlement control, and shallow overburden excavation. They innovatively applied techniques such as refined face pressure control, summarizing a complete set of construction experience for super-large diameter tunnels crossing the suspended river section of the Yellow River. This experience provides a replicable and scalable technical model for the construction of super-large diameter tunnels crossing rivers nationwide.

The Jinan Aerospace Avenue Yellow River Tunnel is a core project in Jinan's "Four Bridges and Four Tunnels" transportation layout. Upon completion, it will further improve the urban road network system on both sides of the Yellow River in Jinan, strengthening connections between urban expressways and surrounding highways as well as key transportation hubs. As an important passage linking Jinan Yaoqiang International Airport with the Start-up Area for New and Old Kinetic Energy Conversion, this tunnel will effectively propel Jinan from the "Daming Lake Era" into the "Yellow River Era," injecting transportation momentum into the ecological protection and high-quality development of the Yellow River Basin and the construction of a strong provincial capital in the new era.