Double-layered pass-through of the world's largest diameter underwater shield tunnel.

On March 17th, with the completion of the last piece of the cast-in-place lane slab, the upper lane slab of the Jinan Huanggang Road Yellow River Tunnel, constructed by China Railway 14th Bureau Group, was fully completed, marking the achievement of dual-layer penetration of the world's largest diameter underwater shield tunnel. It is understood that the Jinan Huanggang Road Yellow River Tunnel is approximately 5.75 kilometers long, with the shield section being approximately 3.3 kilometers long, and constructed using the "Shanhehao" shield machine with a excavation diameter of 17.5 meters. The tunnel has a single-hole double-layer structure, with a total of six lanes on the upper and lower levels, designed for a speed of 60 kilometers per hour, and can achieve the traffic function of two tunnel holes.