青藏高原东缘进藏高等级道路面临的挑战

随着国家"十二五"西部深度开发战略的实施,从青藏高原东缘进藏的高等级道路建设已开始分步启动,有关全线控制性问题与相应关键技术的研究急待开展.介绍了青藏高原东缘进藏交通廊道的概况,在此基础上提出了横跨南北平行岭谷地形的选线设计、海洋性山谷冰川的长程威胁、过断层蠕滑变形带的线路工程设计等我国高等级道路兴建遇到的新问题.最后,以鲜水河方案为例,提出了个体工程布置采用简易工程减少工程损失,方案比选采用期望年换算工程运营费的地震风险调控程式;针对深切峡谷沿河线沟谷灾害链风险,建议采用沿河线走高位的风险绕避策略,从而建立了基于选线设计宏观决策层面的特大灾害风险调控策略框架,可供东缘进藏髙等级道路建设以及康定至林芝段的方案论证参考. 

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.