Abstract: The occurrence of rock bursts during underground engineering construction is closely related to the time-delay failure characteristics of rocks. Dynamic disturbances such as excavation blasting and mechanical drilling directly impact the formation process of rock bursts. Time-delay failure tests on sandstone under dynamic disturbances of varying amplitudes and frequencies were conducted to analyze their impact and mechanism on rock failure delays. Research findings indicate: 1) Under different amplitudes (8%–24%) and frequencies (0.2–1.0 Hz) of disturbances, the incubation time for rock sample failure significantly shortens, by 39.49%–98.21% compared to undisturbed conditions. With increasing frequency and amplitude of the disturbance load, the proportion of the accelerated deformation stage duration in the rock sample gradually decreases, leading to an increase in the sudden failure. 2) Increasing amplitude and frequency of disturbance loads weaken the flaky peeling phenomenon during rock sample failure and increase the randomness of crack generation, altering the time-delay failure form and degree of rock samples. 3) The damage variable of rock samples under dynamic disturbance exhibits an inverted S-shaped growth pattern over time. A time-delay cumulative damage model for rocks considering static loads and dynamic disturbances has been developed. 4) During the static loading stage, the rock sample accumulates elastic energy and incurs initial damage. The dynamic disturbance intensifies the damage evolution process, leading to continuous induction of new damage. Increasing amplitude and frequency of the disturbance accelerates rock damage, causing a reduction in sample bearing capacity and ultimately triggering rock burst. These research findings can provide valuable references for analyzing and interpreting time-delayed rock bursts induced by dynamic forces in deep rock mass engineering.

Key words: dynamic disturbance, time-delayed, rockburst, amplitude, frequency, energy