After the impoundment and operation of reservoirs

the repeated change of water level has “fatigue effect” on the rock mass of the reservoirs slope

and the deterioration of the rock mass under water-rock interaction will affect the stability of the whole slope. Based on these

we acquired the following results on the foundation of the trial data analyses of the immersion-air dry cycle water-rock interaction in earlier stage. According to the characteristics of stress-strain curve acquired in the process of triaxial compression test under the water-rock interaction

and in virtue of continuum damage mechanics and statistical theory

the damage effect of the immersion-air dry cycle water-rock interaction is coupled into the damage statistical constitutive model. The damage constitutive equation of sandstone under water-rock interaction is established by considering the influence of compacted section. Comparative analysis reveals that the calculated curve based on the established sectional statistical damage constitutive model conforms well to the trial curve

which means the statistical damage constitutive model can accurately reflect the damage effect of sandstones under the immersion-air dry cycle water-rock interaction. In the process of water-rock interaction

the constitutive model parameters m and F0 all diminish gradually

which reflect the mechanical characteristics of sandstones that the brittleness weakens and the macroscopic strength reduces gradually. The results of the study can be used as a reference for long-term deformation stability analysis of a large number of existing bank slopes

and the correlation analysis method can also provide reference for similar experiments.