On the morning of September 3, the Renjia Town Tunnel, part of Section 3 of the Yuwanzhou High-Speed Railway station works contracted by China Railway No. 3 Engineering Group, successfully broke through and began excavation. To date, across all 6 tunnels and 10 working faces of Section 3, cumulative excavation has reached 2,006.6 meters, marking major progress in the tunnel construction of the project.

▲ Cumulative excavation of the tunnel works in Section 3 of the Yuwanzhou High-Speed Railway station works exceeds 2,000 meters

The Section 3 project of the Yuwanzhou High-Speed Railway is located within Zhongxian and Fengdu counties, with a total length of 36.01 kilometers, of which the total tunnel construction length is 12.834 kilometers. The longest tunnel, the Bohetian Tunnel at 4,856 meters, is a high-gas tunnel with high construction risk and difficulty, making it a key control project. The tunnel currently entering excavation, the Renjia Town Tunnel, has a total length of 560 meters; its tunnel body consists mainly of soft rocks such as mudstone, which is prone to surrounding rock deformation, and the complex geological conditions make tunnel construction relatively difficult.

▲ Construction site of the tunnel works in Section 3 of the Yuwanzhou High-Speed Railway station works

It is understood that during tunnel construction in this section, a three-dimensional laser profile scanner was used, making overbreak and underbreak control more accurate, rapid, and comprehensive, and meeting construction quality and secondary lining thickness requirements while reducing costs. In response to high gas, the contractor optimized equipment configuration, established a tunnel gas detection and early-warning management mechanism, and carried out explosion-proof modifications to electrical equipment and mechanical operating equipment. At the same time, technical measures combining automatic monitoring systems with manual detection were adopted, along with secure access control systems and personnel positioning systems, to ensure construction safety.