Abstract：With the consideration of geological conditions，the pipe-roofing method―advancing method with relay station，is used in the project of Shanghai Hongxu—Beihong road. It is the first time to use pipe-roofing method to construct tunnel in China，and it is the largest and longest pipe-roofing tunnel in saturated soft soil. There are high construction risks because of large-section culvert box，novel construction method and unfarournble geological conditions. On the basis of risk analysis theory，the construction risks，which exist in advancing precisions of pipe-roofing，earth settlement (upheaval)，pipe damage，waterproof capacity of pipe-roofing，joint types，stability of excavation face，box damage，box advancing direction controlling，pipe settlement，enit safety of box，and ground deformation controlling，are discussed. Total risk level of the project is gained，and the preventing methods are presented.
