7234-Meter Gaosheng No. 2 Tunnel on China's Xi'an-Chongqing High-Speed Railway Breaks Through

en.Wedoany.com Reported - On October 11, the Gaosheng No. 2 Tunnel on the Kangyu section of the Xi'an-Chongqing High-Speed Railway in China completed its final blasting operation, achieving full tunnel breakthrough. The tunnel is located in Kaizhou District, Chongqing, with a total length of 7,234 meters. It was designed by China Railway Eryuan Engineering Group and constructed by China Railway Seventh Group, and is classified as a Grade I high-risk tunnel. As of now, 66 tunnels on the Kangyu section of the Xi'an-Chongqing High-Speed Railway have been completed, and ballastless track, station buildings, and the four electrical engineering systems are underway.

The Gaosheng No. 2 Tunnel passes through various adverse geological areas, including landslides, rock piles, mined-out zones, old kiln water accumulation, and karst. Construction faces risks such as high gas prevention and control, reverse-slope drainage, and karst water inrush and mud outburst. Gas accumulation, water accumulation from reverse-slope operations, and surrounding rock fragmentation and instability in karst sections are the main risk control targets during construction.

The construction team of China Railway Seventh Group established a 24-hour continuous intelligent gas monitoring and manual inspection mechanism, and explosion-proof electromechanical equipment was deployed at the construction site. In response to reverse-slope drainage conditions, the project set up multi-stage pump stations and optimized drainage pipelines, implemented dynamic monitoring of water inflow at the tunnel face, and formulated special emergency response plans.

During tunnel excavation, the construction unit simultaneously carried out advanced geological forecasting and surrounding rock monitoring measurements, adjusted support parameters and construction plans according to changes in the strata and surrounding rock ahead, and implemented gas detection, drainage, and surrounding rock stability control.

The main line of the Kangyu section of the Xi'an-Chongqing High-Speed Railway has a total length of 478 kilometers. It starts from Ankang West Station in Shaanxi, passes through Chengkou in Chongqing, Dazhou and Guang'an in Sichuan, as well as Hechuan and Beibei in Chongqing, and finally connects to the Chongqing West Station hub. The Kangyu section has now entered the stage of ballastless track construction, station building construction, and installation of the four electrical engineering systems—communication, signaling, power, and electrification—with the related works being implemented simultaneously.