Permafrost and Railroad Construction on the Tibetan Plateau

Guodong Cheng¹ and Tingjun Zhang^2
1State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences
²National Snow and Ice Data Center, University of Colorado

The Qinghai-Xizang railroad is under construction on "The Roof of the World"--the Tibetan Plateau, to be completed in 2007. The railroad will cross 550 km of permafrost region over the Tibetan Plateau, 50% of which is high-temperature permafrost and 37% of which is ice-rich permafrost. Predicted climate warming over the Tibetan Plateau in the coming decades would accelerate permafrost degradation. Surface disturbance due to the railroad construction would further destabilize permafrost conditions and seriously damage the ecosystem in the permafrost region. Thawing of warm permafrost over the Tibetan Plateau becomes one of the key issues in the cross-Plateau railroad construction. In this presentation, we will discuss techniques used to prevent permafrost from thawing due both to the climate warming and the surface disturbance of engineering construction. Although several techniques have been used over the Tibetan Plateau, application of crushed rock layer to cool permafrost and maintain permafrost stability is very successful at current stage although further observations are needed. We will also further demonstrate the principles of using the crushed rock layer to maintain permafrost based on data from field investigation, laboratory experiments, and numerical simulations.