On May 21, with the completion of pumping for the last truckload of concrete, the final secondary lining concrete pour for the Shanyuan Tunnel on the Jiyuan–Xin'an Expressway, constructed by China Railway No. 4 Engineering Group, was successfully completed, making it the first tunnel project on the entire Jixin Expressway to have all of its main structures completed, laying a solid foundation for opening to traffic on schedule.

The Shanyuan Tunnel adopts a separated left-and-right tube design, with the left tube 573 meters long and the right tube 595 meters long, a maximum burial depth of 58 meters, and a design speed of 100 km/h. Both the entrance and exit of the tunnel are located on mountain slopes, and the geological structure is complex; the tunnel body passes through interbedded argillaceous sandstone and sandy mudstone, a rock formation with low bearing capacity that disintegrates easily upon contact with water and is prone to accidents such as deformation or collapse.

To ensure that construction of the Shanyuan Tunnel was completed on schedule, in response to the difficulties in its construction, the technical personnel used new technologies such as advanced geological forecasting, monitoring and early-warning, and laser cross-section scanning, along with new equipment including cantilever-type tunnel boring machines, and independently innovated processes, developing the cantilever boring machine excavation construction method for soft-rock tunnels, thereby ensuring safe and efficient excavation.

Through technical improvements, the construction party innovatively used a new type of intelligent secondary lining trolley. The trolley is equipped with systems for void monitoring, layered window-by-window concrete distribution, soft overlap, top-cracking prevention monitoring, and grouting with the formwork in place, enabling visual monitoring of the lining construction and ensuring the appearance quality of the concrete. Intelligent construction equipment and advanced management concepts reduced safety risks in the Shanyuan Tunnel, improved project quality, ensured orderly and controllable construction progress, achieved green construction from the source, and put the concept of ecological civilization into practice.

Once completed, the Jixin Expressway will connect with the Lianyungang–Khorgos, Heze–Baotou, and Xinyi Expressways to form a rapid outer-ring corridor network for Luoyang, and will also become a new trunk line linking northwestern Henan with southeastern Shanxi. It is of great significance for promoting ecological protection and high-quality development in the Yellow River Basin, meeting the travel needs of residents along the route, and advancing regional economic and social development.