Spanning the Jintang Channel between Ningbo and Zhoushan, the tunnel stretches 16.18 kilometers, including an 11.21-kilometer shield section. Two large-diameter shield machines — the "Dinghai" Shield Machine and the "Yongzhou" Shield Machine — are excavating from opposite ends and will meet beneath the seabed.

The project faces extremely challenging geological conditions, involving long stretches of hard rock, clay and silt under high water pressure. Currently tunneling through a permeable and unstable sandy layer, engineers have optimized excavation parameters, strengthened sealing management, and adopted real-time monitoring and synchronous grouting to ensure safe and stable progress.