On the morning of March 18th, the left tunnel of the Kuntinglingtunnel for the Liuheng Highway Bridge (Phase I) successfully broke through, marking a new stage in the highly anticipated construction of the expressway tunnel for the Liuheng Highway Bridge (Phase I).
The Kuntingling Tunnel is located to the north of Kunting Village, Chunxiao Town, Beilun District. It consists of a six-lane continuous arch tunnel in both directions, starting from the Jiangjunshan Bridge and ending at the Wangjialv Bridge. The tunnel has a total length of 513 meters and a maximum burial depth of approximately 84 meters, making it the longest “continuous arch tunnel” for a highway currently under construction in Ningbo.
It is understood that compared to the “separated tunnel” method where the left and right tunnels are excavated independently, the engineering difficulty and construction risk of a “continuous arch tunnel” increase exponentially. However, adopting the “continuous arch tunnel” method can effectively save land.
According to the introduction, villages such as Kunting, Wangjialv, Jiuqin, and Hetou are distributed along this section of the expressway, with densely packed farmlands, making every inch of land precious. It is reported that the distance between the two elevated sections in a separated tunnel is generally more than 20 meters, while in a “continuous arch tunnel,” the distance between the two elevated road surfaces is less than 2 meters.
According to calculations by the project department, by adopting the “continuous arch tunnel” method alone, the Liuheng Highway Bridge (Phase I) can save more than 30 mu (approx. 5 acres) of land, while minimizing the impact on surrounding buildings and maximizing the intensive use of land for the expressway.
According to the construction plan, after successfully completing the breakthrough of the left tunnel, the Kuntingling Tunnel is expected to complete the breakthrough of the right tunnel in June and finish all tunnel construction in September. The entire Liuheng Highway Bridge (Phase I) is also expected to be completed and open to traffic in 2025.