On February 21, construction of the last part of a ballastless track in the No.1 shaft of Anding Tunnel was completed, marking the completion of the main structure of the 17,476-meter-long Anding Tunnel, the longest along the Yuxi-Boten Section of Kunming-Vientiane Railway. The construction project was undertaken by China Railway No.5 Engineering Group.

Construction of the Anding Tunnel was the hardest part for building the China-Laos Railway, posing a series of geological difficulties such as water leak, dense fault zones and high rock temperature. The Yuxi-Boten Railway project department of China Railway No.5 Engineering Group undertook the construction of the entrance section that measures 8,822 meters long.

Building ballastless tracks is the last part of the underground construction of railways. Construction of the first section of the ballastless track of Anding Tunnel started on September 23, 2020. After the main structure of the tunnel was completed, constructors began laying tracks at a speed of five kilometers per day. At present, the track-laying has crossed the whole tunnel. (By Xie Yongbin, He Zengwang and Wei Yuanbin)