Recently, at the construction site of Xiaoxiangling Tunnel in Xide County of Chengdu Kunming Railway Expansion Project (hereinafter referred to as the double track of Chengdu Kunming Railway), the double track of Chengdu Kunming Railway has been completed and is expected to be open to traffic by the end of 2022.

The double track of Chengdu Kunming Railway is a key project of the Western Development of China and an important channel connecting South Asia and Southeast Asia international trade ports in the construction of the the Belt and Road. It is parallel to the existing Chengdu Kunming Railway, with a total length of about 860 kilometers and a design speed of 160 kilometers per hour. The double track of Chengdu Kunming Railway is constructed and opened in sections. At present, Only the Emei Mianning section (hereinafter referred to as the Emein section of Chengdu Kunming double track railway) is about 226km under construction.

The Emein section of Chengdu Kunming double track railway is the section with the most complex topographic and geological conditions and the most difficult construction. There are 49 bridges totaling 30 kilometers, 27 tunnels totaling 170 kilometers, and 6 tunnels more than 10 kilometers long, with a bridge tunnel ratio of 88.6%. It has the typical characteristics of long and deep buried tunnels, and the maximum ramp of the line is 12.7 ‰.Editor/Ma Xue