On August 31, the Luojialiang Tunnel left tube—an important control project on the Chengkou county seat to Beiping interchange section of the Chengkai Expressway—was holed through 5 days ahead of schedule, completing the breakthrough of both tubes of the Luojialiang Tunnel.

The left tube of the Luojialiang Tunnel is 4,233 meters long, and the geological conditions during construction are extremely complex. The tunnel passes through the roughly 400-meter Chengba fault zone and is also constructed on an adverse slope, entailing high safety risks and stringent environmental protection requirements.

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 based on multi-boom rock drilling jumbos.

Chongqing Expressway Engineering Consulting Co., Ltd. stated that the breakthrough of both tubes of the Luojialiang Tunnel marks that the civil works of the Chengkou county seat to Beiping section of the Chengkai Expressway have entered the final decisive stage, pressing the "accelerator" for striving to open to traffic by the end of the year.

The Chengkai Expressway is about 128 kilometers long in total, of which the approximately 110-kilometer section from Zhaojia in Kaizhou to the Chengkou county seat has already opened to traffic. The remaining approximately 18-kilometer section under construction from the Chengkou county seat to the Shaanxi boundary, of which the roughly 11-kilometer Chengkou county seat to Beiping section is expected to open to traffic within this year, has also laid a solid foundation for the full opening of the Chengkai Expressway in 2026 and the creation of a fast corridor between Chongqing and Shaanxi.