The research area of this research project is Zhungeer Banner in the southern part of Erdos, Inner Mongolia, with the local reddish purple sandstone remolded soil as the research object. This test is conducted under different numbers of freeze-thaw cycle and different confining pressure by using TSZ-6A full automatic static triaxial apparatus. The results show that: in each of the freeze-thaw cycles under different confining pressure, Pisha-sandstone remolded soil stress-strain curve presents the characteristics of the strain hardening; stress-strain curve roughly experiences three stages with the increase of axial strain: Nearly completer elastic range and Strain hardening stage and Yielding stage. In order to quantitatively analyze the strength parameters of Pisha-sandstone under different freeze-thaw cycles, the strength parameter degradation coefficients KC and KΦ were introduced, and the degradation trend function of strength parameters was obtained by fitting the degradation coefficient curve.Then analyze the hardening properties and softening properties of stress-strain curve of Pisha-sandstone remolded soil after comparing the relationship between Pisha-sandstone peak strength and residual strength under different numbers of freeze-thaw cycle. Utilize Kq to analyze the deformation of Pisha-sandstone directly.
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