Abstract: Through the analysis of existed triaxial creep test results of red sandstone under the chemical corrosion, it is known that water-rock chemical interaction can accelerate the development of damage and enhance the creep properties of red sandstones. In this paper, based on the chemical kinetic theory of water-rock chemical interaction, the loss of the soluble cement in red sandstone is the key reason for the deterioration of rock mechanical properties under the interaction of chemical corrosion. The chemical damage factor considering the initial pH value and the time is defined by the chemical reaction rate equation and the change of pH value of solution during the immersion process. Meanwhile，based on the generalized Kelvin model, the rheological damage constitutive model of sandstone considering chemical corrosion is proposed. The parameters of the model are identified and verified by the creep results of red sandstone under chemical corrosion. Results show that the proposed model is valid and reasonable, which can well describe the creep properties of sandstones under chemical corrosion.

Key words: sandstone, chemical corrosion, generalized Kelvin model, chemical damage, rheological damage model