In January 8, 10:58, the Changcaogou tunnel of Dunge Railway Gansu Section No.2 Station constructed by CR3 had been run-through victory, which laid a solid foundation for the successful complete of all construction goals. Dunhuang Railway Company gave a commendation briefing.

Dunge Railway is an important rail artery for implementing the "Belt & Road Initiative", it will be further improved the layout of the Northwest Railway Network. Dunge Railway Changcaogou tunnel is located in Aksekazak autonomous county, Jiuquan city, the entrance of tunnel is located in Jinshan north slope, the exit of the tunnel is connect with Changcaogou Bridge, the total length is 2488 meters. The surrounding rock of the tunnel is complex in structure, with frequent changes in various strata such as quartz schist, strong weathered rock, coarse angle grain also with fine breccias. It is one of the key as well as difficult control tunnels across the whole line in the construction of Dunge Railway.

Since the project started, the project participation staff to overcome the altiplano plateau climate, tunnel rock crushing collapse as well as other unfavorable factors. Using the method of tunneling in the tunnel through the broken zone, the curvature of the arch section as well as the amount of deformation reserved by the arch, the tunnel arch deformation as well as terminal deformation are effectively controlled to ensure the orderly, controllable safety of the tunnel lining.