Abstract
Uplifting phenomena of underground tube structures was analyzed by FEM liquefaction code. Uplifting initiates as the excess porewater ratio of surrounding soil layers exceeds over 0.8. Uplifting continues constantly although the fluctuation of surrounding excess pore water pressure or amplitude of vibration.
The soil improvement method and the earth nailing method as countermeasures for uplifting were investigated using same FEM code. It was found that the countermeasures treated underneath of the tube is more effective than that at the head of the tube.
