To study the strength and deformation characteristics of frozen clay under complex stress path

a series of directional shear tests on saturated frozen clay is conducted under different negative temperature conditions by using dynamic hollow cylinder testing apparatus of frozen soils (FHCA-300). Stress-strain curves of the axial and torsional shear components for frozen clay are analyzed under different shear directions. The shear deformation

anisotropy and shear band characteristics are discussed. And the effects of temperature

angle of major principal stress direction

mean principal stress and coefficient of intermediate principal stress in the strength and deformation behaviors of frozen clay are explored. The test results indicate that the value of the mean principal stress p has a significant effect on the stress-strain curves of frozen clay. When p=4.5 MPa

the frozen clay has a major shear strength and this stress value (the mean principal stress) may be the critical value of pressure melting. The anisotropy of frozen clay may be induced by the change of major principal stress direction. Shear strength decreases versus the increase of angle of major principal stress direction. The axial strength decreases with the increase of the coefficient of intermediate principal stress

but the effect of the coefficient on the shear strength is neglect. With the decrease of temperature

the strength of frozen clay increases gradually. Meanwhile

the samples produce brittle failure

and a shear failure surface appears and develops. The shear strength of frozen clay depends mainly on the cementation force between soils and ice particles.