2. Qinghai–Tibet Railway

The Qinghai–Tibet plateau, with an average altitude of more than 4000 m, is known as the “roof of the world” and the “third pole of the earth” and has long been regarded as a “forbidden zone of human life.” Qinghai–Tibet railway (QTR) is a landmark project to implement the Western development strategy and one of the four major projects in the new century in China. The railway with the length of 1956 km starts from Xining, Qinghai in the east and ends at Lhasa, Xizhang in the west. Among them, the 814 km section from Xining to Golmud was completed in 1979 and put into operation in 1984. The QTR starts from Golmud, passes through Nachitai, Wudaoliang, Tuotuohe, Yanshiping, crosses Tanggula mountain, goes through Ando, Naqu, Dangxiong, Yangbajing of Tibet autonomous region, and ends at Lhasa, with a total length of 1142 km. Among them, the newly built line is 1110 km, which was officially started on June 29, 2001, and officially opened to traffic on July 1, 2006 [1‐3]. Figure 2.1 shows the schematic diagram of the line between Golmud and Lhasa of QTR.