Abstract：Great challenges have been encountered in the construction of Fenghuoshan tunnel due to its chilly climatic and plateau conditions，which consist of the following：how to construct the tunnel without harm to frozen soils，how to employ special techniques to adapt to the absence of oxygen in the plateau，and how to avoid the frost heaving in frozen soils. Accordingly，a series of techniques have been adopted to overcome these difficulties，which include a heat insulation layer between the lining and initial supporting of the tunnel，an intact waterproof and drainage system，and special construction technique for concrete at low temperature to alleviate the frost damage. Owing to these techniques，the Fenghuoshan tunnel has been successfully constructed .
