Workers engage in tunnel construction. [Photo/zhoushan.cn]

The new components for the tunnel automatic hanging formwork trolley arrived at the Tiancai Kengang Tunnel section of the Ningbo-Zhoushan Expressway double-track project on April 16. 

The trolley will speed up tunnel construction by a factor of three to five time compared to human labor once it is assembled in five days, reducing human errors and enhancing the sealing integrity of the waterproof layer.

Starting in Feburary this year, mechanized equipment such as double-arm rock drilling trolleys, triple-arm rock drilling trolleys, and arch anchoring and grouting machines have been gradually introduced into the tunnel construction process, improving efficiency and safety.

With mechanized construction in place, the tunnel's monthly footage has increased from 80 to 120 meters to 150 to 200 meters. Modular scheduling has enabled continuous operations, resulting in significant reductions to key project timelines.

The lengths of the left and right tunnels at Tiancai Kengang are 2,375 meters and 2,547 meters, respectively, with approximately 470 meters and 560 meters excavated so far, accounting for about 25 percent of the total work. Full connectivity is expected by October next year.