According to experiments on granite under uniaxial compression at high temperatures (normal to 850 ℃) and after high temperatures (normal to 1 200 ℃) cooling and reloading

the mechanical properties of granite have been researched. The variations of uniaxial compressive strength

elastic modulus

longitudinal wave velocity

cut-slip strain with temperature are analyzed; then the effects of thermo-mechanical coupling are studied. Some results are achieved: (1) The peak strength and elastic modulus decrease continuously at high temperature. (2) Reloading after high temperature

the strength changes little from 25 ℃ to 600 ℃

then decreases suddenly at about 800 ℃. (3) The longitudinal wave velocity decreases gradually as temperature rises. (4) The cut-slip strain is small

and varies little below 800 ℃

then increases rapidly and the granite presents distinct plastic behavior over 800 ℃. (5) Based on the proposed concept of thermo-mechanical coupled factor

one-dimensional nonlinear thermo-mechanical coupled damage constitutive equation is established; and model curves are in agreement with experimental curves.