Abstract:

Taking the shield boring of Nanjing Metro in fine silty sand ground as an example, the author analyzes the main risks in tunnel boring and summarizes the construction countermeasures, particularly in aspect of water inflow, sand inflow, ground surface settlement and building/structure deformation. In the end, the risks have been brought under effective control. The countermeasures presented in the paper, especially those for shield boring under brickmasonry workshops without foundations, can provide reference for similar projects in the future.

Key words: fine silty sand ground  , ground liquefaction  , risk analysis  , settlement control  , countermeasure