After 26 months, on the morning of August 31, the left tube of the Luojialiang Tunnel in the section from Chengkou County seat to Beiping Interchange of the Chengkai Expressway was holed through, 5 days ahead of schedule, marking the completion of both tubes of the Luojialiang Tunnel. The Chengkou County seat to Beiping section (about 11 km) is expected to open to traffic within this year.

"The left tube of the Luojialiang Tunnel is 4,233 meters long, and the geological conditions during construction are extremely complex. The tunnel body passes through the roughly 400-meter Chengba Fault Zone and is constructed on an adverse slope, posing high requirements for safety risk control, civilized construction, and environmental protection," said a person in charge from China Railway 12th Bureau. To ensure smooth tunneling, the project continued to use the comprehensive advanced geological forecasting system of the Chengkai Tunnel, promptly analyzing geological issues identified in the forecasts, predicting adverse geological conditions ahead of the tunnel face, and dynamically adjusting the construction plan, while fully promoting mechanized construction centered on multi-boom rock drilling jumbos.

According to a person in charge from the consulting company of Chongqing Expressway Group, the subsequent ancillary works are expected to be fully completed by mid-November. The breakthrough of both tubes of the Luojialiang Tunnel marks that the civil engineering works of the Chengkou County seat to Beiping section of the Chengkai Expressway have entered the final decisive stage of full completion, and has also pressed the "accelerator" for opening to traffic by the end of the year.

The Chengkai Expressway has a total length of about 128 km, of which about 110 km from Zhaojia in Kaizhou to the Chengkou County seat has already opened to traffic. The remaining section under construction, from the Chengkou County seat to the Shaanxi boundary, is about 18 km long, of which the Chengkou County seat to Beiping section (about 11 km) is expected to open to traffic within this year. This also lays a solid foundation for the full opening of the Chengkai Expressway in 2026 and the creation of a fast corridor between Chongqing and Shaanxi.