On January 5, the inclined shaft of the Yeheshan Tunnel on the Linyou–Famen Temple Expressway was successfully holed through and entered main tunnel construction, marking major progress in the excavation of the Yeheshan Tunnel on the Linfa Expressway and laying a solid foundation for the completion and opening of the entire project.

The Yeheshan Tunnel is a controlling project of the entire Linfa Expressway. It is designed as a curved separated extra-long tunnel, with a left tube 8,130 meters long and a right tube 8,135 meters long, and a maximum buried depth of the tunnel invert of 532 meters. It involves difficulties such as poor surrounding rock stability, high safety risks, and high requirements for environmental protection and soil and water conservation.

The inclined shaft of the Yeheshan Tunnel is a permanent ventilation shaft for the tunnel, and during construction it is used for construction transport and to provide additional tunnel construction working faces. The shaft portal is about 4.1 kilometers from the tunnel entrance, and the shaft has a total length of 1,530 meters, of which the air supply duct, exhaust duct and transport passage at the shaft bottom are 166 meters long. The design elevation of the shaft bottom is 1,021.51 meters, and the design elevation of the portal is 1,170.0 meters. Trackless transport is adopted in construction.

To ensure construction safety, before excavation the contractor used methods such as the TSP203 geological prediction system, advance drilling, ground-penetrating radar and advance geological prediction to detect in advance the rock strength, lithology, degree of rock fragmentation, and water inflow pressure and volume in fault fracture zone sections, and correctly selected excavation methods, grouting parameters and corresponding technical parameters, thereby achieving normal construction progress through informatized management.

After the inclined shaft was holed through, an additional construction working face was provided for the Yeheshan Tunnel, laying the foundation for the early holing-through of the tunnel and ensuring that the entire line opens to traffic on schedule. After the Linfa Expressway is completed and opened to traffic, a new corridor connecting north and south will be opened in eastern Baoji, forming a major traffic loop linking the Hefeng Expressway and the Lianhuo Expressway, and playing a very important role in accelerating the improvement of regional traffic conditions and promoting the development of the Linbei coalfield along the route, the outward transport of agricultural and sideline products, and the development of the tourism industry.