On July 16, the Dadaodi Tunnel of the Zhejiang Communications Group's Yongtaiwen Reconstruction and Expansion Taizhou North Section Project was successfully holed through. This tunnel is the ** tunnel on the entire project line to be holed through, laying a solid foundation for achieving full completion and opening to traffic.

Dadaodi Tunnel successfully holed through

The Yongtaiwen Reconstruction and Expansion Taizhou North Section Project has a total of 7 tunnels along its entire line. Among them, the Dadaodi Tunnel is located in Huixi Town, Linhai City, Taizhou, within the Maoliling Tunnel Group. It adopts the reconstruction and expansion form of a newly built three-lane tunnel on the left side, with a single-side tunnel length of 260 meters. After holing through, it can effectively alleviate traffic congestion pressure.

Although the Dadaodi Tunnel is not long in mileage, its minimum distance from the existing tunnel is only 21 meters, and its minimum distance from the Hangzhou-Shaoxing-Taizhou Railway is only 98 meters. Moreover, the entire length of the tunnel lies within the railway blasting protection zone, so there are many construction constraints and relatively high technical difficulty. To this end, the project actively coordinated with the railway department and completed multiple trial blasts during railway operation windows. At the same time, when excavation reached 15 meters from the tunnel exit, the method was changed from blasting excavation to mechanical excavation to fully ensure the safe operation of the expressway and railway. Since entering the tunnel in March 2024, after more than one hundred days of intensive work, the tunnel has finally been holed through.

To reduce the impact of construction on expressway traffic, the participating units strictly controlled the blasting vibration velocity, carried out synchronous monitoring of the existing tunnel, and adopted measures such as pre-reinforcement and emergency reinforcement to ensure the structural safety of the existing tunnel. During construction, the project strictly followed the requirements of "active guidance, passive protection, all-time assurance, and isolation and enclosure," setting up targeted conspicuous signs and multi-level advance warnings, installing blast isolation nets and bamboo racking, and properly carrying out safety protection for each blast at the tunnel portal, effectively controlling blasting flyrock and ensuring driving safety and smooth construction progress.

The Yongtaiwen Reconstruction and Expansion Taizhou North Section Project starts at the Mao'aoiling Tunnel at the junction of Ninghai and Sanmen County on the Yongtaiwen Expressway, passes through Sanmen County and Linhai City, and ends at the Linhai South Interchange, with a total route length of 42.835 kilometers, a construction period of 48 months, and a planned completion by the end of 2026.

At present, all 7 tunnels of the project have entered tunnel construction, and the Maoliling Tunnel Group has completed about 2.1 kilometers of excavation, with overall progress at 45%. The project has completed a cumulative investment of 5.1572 billion yuan, accounting for 43.3% of the total investment of 11.922 billion yuan. After the project is completed, it will accelerate Taizhou's integration with Ningbo to the north, Wenzhou to the south, Jinhua-Yiwu to the west, linkage with Hangzhou Bay, and connection with Greater Shanghai, fully integrate into the integrated development of the Yangtze River Delta, effectively enhance the traffic capacity and service level of the national expressway network, strengthen the collection and distribution and national defense readiness transport capacity of Zhejiang's eastern coastal ports, and accelerate the construction of the Zhejiang Marine Economy Demonstration Zone.