Abstract: In order to investigate the law of failure and deformation of statically loaded rock under periodic load, by using the Instron electro-hydraulic and servo-controlled material testing machine, uniaxial test of red sandstone subjected to static-dynamic coupling loading is carried out. Furthermore, by way of combining uniaxial horizontal static loading device made by self and Instron electro-hydraulic and servo-controlled material testing machine, biaxial test of red sandstone subjected to static-dynamic coupling loading is performed. Experiment indicates that the failure mode of statically loaded red sandstone under periodic dynamic load changes according to different static stress states. The hysteresis loop of stress-strain curves of statically loaded red sandstone under period dynamic load is first sparse, and then dense, and then sparse, afterwards rock failure appears. Although the number of hysteresis loop and the value of complete strain of stress-strain curves of the same statically loaded red sandstone under different periodic dynamic loads are different, deformation of statically loaded red sandstone under period dynamic load obeys to the law of ultimate deformation of rock under period load; and there is tendency to the same equivalent complete strain energy of rock failure.

Key words: static-dynamic coupling loading, statically loaded rock, rock fatigue failure, stress-strain curve of rock, rock ultimate deformation law