Recently, the Nawu Tunnel, a control project of the Baise North-South Bypass Line (Section 5 of the Baise North Ring Line), successfully surpassed the 1,000-meter mark in cumulative single-tube excavation. This milestone marks major progress in tunnel construction for the section, laying a solid foundation for the early breakthrough of the tunnel and providing a strong boost to the Baise Ring Expressway.

The Nawu Tunnel is located in Nawu Village, Youjiang District, Baise City, Guangxi Province. It is a separated tunnel laid out along a curve, with a total length of 2,185 m (right tube), making it the longest tunnel in the entire route design. The maximum buried depth of the tunnel is approximately 257.5 m. The surrounding rock throughout the tunnel is Class IV and Class V, with Class V accounting for 65%. The tunnel passes through multiple fault fracture zones and features unfavorable geology such as soft strata, shallow-buried unsymmetrical loading, and water and mud inrush strata. The project department adopted measures at the construction site including advanced geological drilling, pipe-roof grouting reinforcement, and curtain grouting to minimize construction risks to the greatest extent and successfully navigate the influence of complex strata. To date, cumulative single-tube excavation has reached 1,005 m.

To better accelerate project construction, the contractor optimized construction procedures and organizational management, persisted in quality and safety standardized management, optimized the construction organization design, and innovated construction methods. The site is equipped with advanced tooling and equipment such as an automatic secondary lining distribution trolley, hydraulic fabric-hanging trolley, hydraulic trestle bridge, and wet-shotcrete robotic arm, achieving mechanized supporting operations across all processes. Meanwhile, the tunnel is equipped with personnel and vehicle access management systems, electronic positioning systems, construction environment gas monitoring systems, safety video surveillance systems, and emergency voice broadcast systems. In view of the characteristics of tunnel construction and based on advanced technologies such as IoT, digitalization, and networking, and supported by safety and early-warning management mechanisms, an effective combination of "system-personnel-environment-process" has been used to build a multi-source information collection system and an intelligent business monitoring and early-warning system, forming an intelligent tunnel construction monitoring and early-warning management platform integrating data analysis, risk control, safety supervision, and emergency command. This has realized a new five-in-one management model of "perception, analysis, service, command, and supervision" for tunnel construction.

It is reported that the Baise North-South Bypass Line (Baise North Ring Line) is an express corridor connecting Guangxi and Guizhou. Once completed, it will bring Tianyang District, Baidong New Area, and the main urban area of Baise within the service circle of the expressway ring line. This will greatly expand the urban development space of Baise City, further improve and clarify the functions of regional trunk highways, and enhance the traffic capacity of trunk corridors. At the same time, the opening of this route will promote the integrated development of Baise-Tianyang-Tiandong and build a "half-hour economic circle" among Baise, Tianyang, and Tiandong.