Abstract: The deformation and strength characteristics of mudstone were studied by using MTS 810 Rock Mechanics Servo-Controlled Testing System and MTS 652.02 High Temperature Furnace under the action of temperatures ranging from room temperature to 800℃. Although the experimental results have some certain discreteness, they also have obvious overall regularity. The elastic modulus and peak of strength increase when the temperature is between room temperature and 400℃, while they decrease rapidly when the temperature is over 400℃. Based on rock damage mechanics and statistical strength theory, combining mechanical properties of mudstone at high temperature, the damage evolution equation and constitutive model of mudstone, considering effects of temperature and loading speed, are established. Furthermore, aimed at mechanical properties of tested mudstone, the corresponding detailed parameters of damage equation are given and constitutive model has a good agreement with the experiment results.

Key words: high temperature effect, mudstone, deformation characteristic；strength characteristic；damage evolution