A TRUE TRIAXIAL CREEP CONSTITUTIVE MODEL FOR ROCK CONSIDERING HYDROCHEMICAL DAMAGE

In order to accurately describe the characteristics of each stage of rock creep behavior under the combined action of acid environment and true triaxial stress, based on the chemical kinetic theory of water-rock interaction, a chemical damage factor considering pH and time is defined. The elastic body, nonlinear Kelvin body, linear Kelvin body, and visco-elastic-plastic body are connected in series, and the actual situation under the action of true triaxial stress is considered at the same time, a damage-creep constitutive model considering the coupling of rock acid corrosion and true triaxial stress is established. The parameters of the deduced model are identified and verified with the existing experimental research results. The yield surface equation of rock under true triaxial stress is obtained by data fitting, and the influence of intermediate principal stress on the creep model is discussed. The results show that the derived constitutive model can well reflect creep properties of the rock under acid corrosion The true triaxial creep characteristics under the action have certain rationality and practicability.