The deformation characteristics of frozen soil are important parameters for testing the stability of foundation deformation in foundation design of cold region

changing with the change of stress direction. However

the influence of principal stress axes direction on the deformation characteristics of frozen soil is rarely considered in existing studies. This paper carries out a series of principal stress unidirectional rotation tests on frozen clay by using frozen soil hollow cylinder apparatus. The influence of rotation rate and rotation direction of principal stress angle α on deformation characteristics of frozen clay is explored. It is found that plastic deformation can be generated in the frozen clay without changing the stress amplitude in pure principal stress axes direction rotation tests. The strain peak of frozen clay lags behind the stress peak in the deformation process. The α-angle rotation rate can affect the axial strain and shear strain of frozen clay

and there is a critical α-angle rotation rate to make the frozen clay play better carrying capacity. Different α-angle rotation direction changes the stress process of frozen clay

and the larger the shape variable of frozen clay

the more obvious the influence of α-angle rotation direction on its deformation development. Through the analysis of the hysteresis curve

it is found that α-angle rotation rate will have a greater impact on the strength of the frozen clay when the α-angle rotation rate is small. Nevertheless

its impact on the strength of frozen clay will be reduced when the α-angle rotation rate is large. The influence of α-angle rotation direction on the strength of frozen clay is closely related to the selection of stress path parameters.