Recently, the right tube of the Taowan Tunnel, the seventh tunnel of the reconstruction project of the Qiaoxia-Qiaotou section of National Highway 330 in Yongjia, broke through, marking the full breakthrough of all tunnels in the National Highway 330 reconstruction project. The project is an important item in Yongjia County's "13th Five-Year Plan" transportation plan and one of Yongjia County's national and provincial highway upgrading projects. At present, construction is continuing to be pushed forward at full speed.

At the construction site of the Taowan Tunnel on the Qiaoxia-Qiaotou section of National Highway 330 in Yongjia, workers are cleaning up the tunnel site in preparation for the secondary lining at a later stage. The Taowan Tunnel has a total length of 238 meters and adopts a separated twin-tube design with two-way four lanes and a design speed of 80 km/h.

According to reports, the surrounding rock of the tunnel is relatively poor among all the tunnels, and during construction there were phenomena of broken surrounding rock and falling blocks, which greatly increased the difficulty of construction. The construction team overcame numerous difficulties and, after nearly nine months of hard work, achieved the breakthrough of the right tube of the Taowan Tunnel. The project has reached an important milestone, marking the completion of the main structure construction of bridges and tunnels along the entire line. According to reports, the excavation of the tunnel body has now been completed, and next the secondary lining construction and subsequent electromechanical ancillary works will be undertaken. All construction inside the tunnel is expected to be completed in November this year.

It is understood that the reconstruction project of the Qiaoxia-Qiaotou section of National Highway 330 has a total length of 17.88 kilometers. The main line starts in Lu'ao Village, Qiaoxia Town, and runs from east to west, ending in Linfu Village, Qiaotou Town, passing through a total of 15 villages and communities in two townships. It adopts the standard of a two-way four-lane first-class highway with a design speed of 80 km/h and a standard subgrade cross-section width of 24.5 meters. At present, in terms of physical works, the subgrade works are 91% complete, the pavement works 9% complete, the bridge and culvert works 95% complete, and the tunnel works 89% complete. Among them, the substructures, T-beam erection and cast-in-place box girders of all 14 bridges along the line have been completed, and construction of the bridge deck system and ancillary works is now underway; all seven tunnels have achieved breakthrough of both tubes.

Schematic diagram of the Qiaoxia-Qiaotou section reconstruction project

National Highway 330 is a major transportation artery running along the north bank of the Ou River through southern Yongjia. Once the project is completed, it will be of great significance for improving the national and provincial highway trunk network and for the economic and social development of areas such as Qiaotou, Qiaoxia and Jinxi.