Abstract：Three groups of experiments are designed to study the damage evolution law of rock under cyclical impact loadings. In these experiments，different grades of confining pressures，impulsive forces and times of shock are considered to have some effects on the damage degree evolution of rock. Simulating impact loadings to marble test cylinders have been accomplished on compression test machine；and the velocities of ultrasonic in damaged marble test cylinders are actually measured. The variation of ultrasonic velocity is used to describe the damage degree evolution of rock under the actions of cyclical impact loadings. The influence regulation of impulsive force and times of shock on the damage degree evolution under cyclical impact loadings are obtained. The results illustrate that the damage degree evolution of marble test cylinders have close correlations with confining pressures，the grades of impulsive force and the times of shock. Under the same confining pressure grade，the damage evolution is determined by the times of shock and the grade of impulsive forces. When the grade of impulsive forces keeping unchanged，the damage evolution is determined by the times of shock and the grade of confining pressures. As confining pressure being raised，the damage depth evolution speed of marble test cylinder under the same cyclical impact loading is reduced with the increasing of times of shock. It is also proved that the effect of confining pressure on the damage degree evolution is affected by the grades of impulsive force under the same shock times. The existence of confining pressure increases the impulsive strength of marble test cylinders.
