Abstract: The frozen soil wall can be simplified as the functionally graded material (FGM) thick cylinder with parabolic-distributed elastic modulus and cohesion. In consideration of the intermediate principal stress, the analytical solutions of the elastic ultimate load, the elastioplastic stress field and the plastic ultimate load are derived based on the unified strength theory. The results are further compared with that of a homogeneous model, the influence of the parameters of unified strength theory is investigated as well. The results show that the stress distribution of FGM frozen soil wall differs from that of homogeneous frozen soil wall, especially the circumferential stress changes from linear distribution to parabolic distribution. The maximum circumferential stress appears in the central thickness instead of the inner or outer wall. The elastic ultimate load is higher but the plastic limit load is lower than that of homogeneous frozen soil wall. The elastic ultimate load and the plastic ultimate load, the radial stress and the circumferential stress will increase with the increase of the parameters of unified strength theory. The conclusions can provide theoretical reference for the design of frozen soil wall.

Key words: frozen soil wall, functionally graded material, parabolic distribution, unified strength theory, elastoplastic analysis, ultimate load