Abstract: In order to better obtain the long-term deformation characteristics of deep underground concrete structures,the uniaxial mechanical properties and creep properties of concrete are tested by TAW-2000 test system. The creep deformation law of concrete under different stress and the long-term strength of concrete are analyzed. Without considering the internal heat exchange of rock,the accelerated creep of rock is studied by the law of conservation of energy,and the damage creep model of concrete based on the principle of conservation of energy in one-dimensional state is established. On this basis,it is assumed that the mechanical parameters and rheological parameters of concrete structures in deep underground engineering are functions of time. An unsteady creep model based on the principle of energy conservation is constructed. The results show that the damage creep model of concrete based on the principle of energy conservation can better describe the whole creep process curve of concrete. The correlation coefficient between the model curve and the test curve is above 0. 95. This shows the correctness of the creep damage model established in this paper. The model not only accurately reflects the creep characteristics of the attenuation and stable creep stages. The shortcomings of accelerated creep are also well described.

Key words: concrete structure,creep properties,the law of conservation of energy,unsteady creep model