Challenges in Construction of Railway and Highway from Sichuan to Tibet through Eastern Margin of Tibetan Plateau

The construction of railway and highway to Tibet through the eastern margin of the Tibetan Plateau has started step by step as the implementation of the Western Development Strategy. The controlling problems in the construction and the corresponding key techniques need to be studied urgently. The general information of railway and highway to Tibet through the eastern margin of the Tibetan Plateau was introduced. Some new challenges in the construction were discussed, including the crossing alternate plateau and ravine terrains in the north-south direction, the long-range threat of maritime valley glaciers and the line engineering design in fault creep deformation zones. A seismic hazard control method was proposed based on the case study of Xianshuihe. In this method, simple projects are adopted to reduce loss in design of individual engineering, and the expected annual operating cost is used to the comparison and selection of schemes. Meanwhile, for routes along deep-cut river, a higher elevation design was suggested to avoid the damage of valley disaster chain. Based on the above works, the framework of extreme disaster hazard control was established for macroscopic location design to provide references for the construction of railway and highway to Tibet and the scheme demonstration for the Kangding-Nyingchi line.