The rebuilt 160km/h double-track line links Miyi with Panzhihua and passes through very difficult terrain. The project required the construction of 13 tunnels with a total length of 55km and 18 bridges totalling 5.56km.
The 12.4km-long Yakou tunnel traverses six sets of strata and seven regional faults. The 12.76km Ranjiawan tunnel passes through the unique Xigeda stratum in the Panxi area. The stratum can disintegrate easily after being immersed in water.
The project also faced numerous obstacles, including large surface structures beneath the 186 million m3 Majiatian tailings reservoir, high-rise buildings in residential areas, and a large artificial lake in Huacheng New District, the bottom of which is only 5m above the top of a tunnel, which made the design and construction extremely difficult.
The main span of the Panzhihua Jinsha River bridge is 208m, which is the largest span prestressed-concrete low-tower cable-stayed bridge in China. CR says this is the first bridge in China to adopt anchoring technology of the upper cable beam anchor block. The bridge also features China’s largest tonnage hyperboloid spherical bearing and uses a shear tenon vibration isolation system. CR says using this technology has given it valuable experience for future railway construction projects where bridges require large spans to cross deep river valleys.
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