Strength weakening effect of high static pre-stressed granite subjected to low-frequency dynamic disturbance under uniaxial compression

Abstract

This study aimed to elucidate the strength weakening effect of high static pre-stressed rocks subjected to low-frequency disturbances under uniaxial compression. Based on the uniaxial compressive strength (UCS) of granite under static loading, 70%, 80%, and 90% of UCS were selected as the initial high static pre-stress (σp), and then the pre-stressed rock specimens were disturbed by sinusoidal stress with amplitudes of 30%, 20%, and 10% of UCS under low-frequency frequencies (f) of 1, 2, 5, and 10 Hz, respectively. The results show that the rockburst failure of pre-stressed granite is caused by low-frequency disturbance, and the failure strength is much lower than UCS. When the σp or f is constant, the specimen strength gradually decreases as the f or σp increases. The experimental study illustrates the influence mechanism of the strength weakening effect of high static pre-stress rocks under low-frequency dynamic disturbance, that is, high static pre-stress is the premise and leading factor of rock strength weakening, while low-frequency dynamic disturbance induces rock failure and affects the strength weakening degree.