On February 16, the Fengshuliang extra-long tunnel on the Anlan Expressway, constructed by the Third Company of China Railway 14th Bureau Group, achieved double-tube breakthrough. It is the first extra-long tunnel to break through on the Langao-Shaanxi-Chongqing Border section of the Anlan Expressway, six months ahead of schedule, marking a major breakthrough in the project's construction.

The Langao-Shaanxi-Chongqing Border section of the Anlan Expressway is a component of the national expressway Yinbai Line (G69) and an important interprovincial corridor linking Shaanxi and Chongqing. The project starts within Langao County, connecting with the already completed Ankang-Langao Expressway, extends south to the main ridge of the Daba Mountains, and ends at the Shaanxi-Chongqing provincial (municipal) border of the Daba Mountain extra-long tunnel, where it connects with the Chengkou (Shaanxi-Chongqing Border)-Kaixian Expressway under construction in Chongqing. The route is 41.14 km long.

The Fengshuliang extra-long tunnel is located in Siji Town, Langao County, and crosses the mountain ridge to Taohe Town. It is 4.79 km long with a maximum burial depth of nearly 698 m, is divided into left and right tubes, and contains fault fracture zones exceeding 1,000 m. It is the longest tunnel on the Langao-Shaanxi-Chongqing Border section of the Anlan Expressway apart from the Daba Mountain extra-long tunnel. The engineering geological conditions along the tunnel are complex: the portal is high and steep with severe unsymmetrical loading, making entry difficult; the surrounding rock in the tunnel is unstable; and long fault fracture zones, dense joint zones, and lithological boundaries occur in many sections, resulting in great construction difficulty and extremely high safety risk.

Zhang Linqing, project manager of the Anlan Expressway project of the Third Company of China Railway 14th Bureau Group, said that to complete the construction task efficiently and with high quality, the builders attached great importance to scientific research and technological innovation. Experts were invited on multiple occasions to lead the project department's technical team in on-site surveys, and analysis was carried out focusing on the four aspects of "safety, quality, environmental protection, and schedule." The location, length, and gradient of construction access passages were discussed repeatedly to optimize the construction plan. By strengthening safety control, strictly grasping project quality, and rigorously organizing construction, the builders effectively overcame construction challenges such as shallow cover, faults, and water-rich conditions, achieving the expected goal of "zero accidents." At the same time, resources were strengthened and investment increased to ensure construction quality, safety, and progress.

The Anlan Expressway is an important corridor for strengthening communication and cooperation among the three major economic regions of Guanzhong-Tianshui, Chengdu-Chongqing, and the Yangtze River. It is of great and far-reaching significance for promoting the development of tourism resources along the route, driving rapid local economic development, significantly improving transportation conditions in southern Shaanxi, increasing cultural exchange between provinces, giving full play to Ankang's geographical advantage of "connecting south and north," and boosting economic development in the revolutionary old areas of the Qinba Mountains.