On October 18, after more than 1,100 days of continuous effort, the Bazi Tunnel on the Chongqing–Qianjiang section of the Chongqing–Xi'an High-Speed Railway was successfully holed through, providing important assurance for the scheduled progress of the entire line.

The Bazi Tunnel is located within Banan District, Chongqing. It is a single-tube, double-track tunnel with a total length of 5,471 meters. The tunnel is dominated by soft surrounding rock such as mudstone intercalated with sandstone, which softens easily when exposed to water; the geological conditions are poor and the safety risk is relatively high. In addition, reservoirs and rivers are distributed along the tunnel route, making construction conditions complex; collapse and settlement are prone to occur during construction, making the work highly difficult.

Yang Hao, deputy manager of Section 4 of the China Railway 11th Bureau Group on the Chongqing–Qianjiang Railway, said: "After the tunnel is holed through, we will complete ancillary works such as the invert, secondary lining and cable troughs within two months, providing a passage for bridge erection and laying the foundation for holing through the entire line."

It is reported that the Chongqing–Qianjiang section of the Chongqing–Xi'an High-Speed Railway is an important part of the national medium- and long-term railway network plan and the Xiamen–Chongqing high-speed railway main corridor of the "Eight Vertical and Eight Horizontal" high-speed rail network. It starts at Chongqing Station and ends at Qianjiang Station, with a total length of 265 kilometers and a design speed of 350 kilometers per hour. After completion and opening to traffic, the travel time from downtown Chongqing to Qianjiang District will be shortened from the current 4 hours to less than 1 hour. At the same time, it will connect with the Chongqing–Zhangjiajie–Changde Railway and the Changde–Yiyang–Changsha Railway, linking the line to the urban agglomeration in the middle reaches of the Yangtze River; it is a corridor for high-speed passenger transport exchange among the Chengdu–Chongqing urban agglomeration, the urban agglomeration in the middle reaches of the Yangtze River, and the West Coast urban agglomeration.