Abstract: A great number offrozen clay specimens are used for the long-term creep testsunder single-axial stress states. The results of experiment show thatthe transient deformation of the soil can be neglected and a simple yieldingfunction can be used to replace the linear Newton element, to improvethe Nishihara modelfor the triaxial nonlinear creep of frozen clay. By means of that improved model, a formula is derived to calculate thestress and displacement field of frozen wall.Calculationresults are close to actual situations.