On January 18, colorful flags fluttered and firecrackers sounded at the exit of the Bojiwan Tunnel on the Dingxi-Lintao Expressway in Lian'erwan Township, Lintao County, where a ceremony was held to mark the breakthrough of the tunnel's right tube, constructed by the Third Branch of China Railway Seventh Group.

The project achieved a phased victory with high standards, high quality and high efficiency, laying a solid foundation for the smooth opening of the Dingxi-Lintao Expressway.

It is understood that the right tube of the Bojiwan Tunnel is 2,113 m long. The surrounding rock of the tunnel body consists mainly of loess, mudstone and argillaceous sandstone interlayers, all designed as Grade V surrounding rock, with a maximum burial depth of about 200 m. The Dingxi-side portal is located on the hillside to the right of a loess gully, at the rear edge of a loess landslide, while the Lintao-side portal is located at the foot of a concave hillside, above a collapse deposit. Construction carries high safety risks and great difficulty. Since the start of construction, after 500 working days of tenacious effort, the Third Branch of China Railway Seventh Group promptly resolved bottleneck and obstruction problems and advanced the work through the joint efforts of multiple parties. Under the premise of ensuring safety and quality, the tunnel breakthrough was achieved, providing an effective guarantee for the opening of the entire line.