Abstract:
To obtain effective methods for reducing the dynamic hazard of rock burst and improving the stability of the surrounding rock-support system, a simplified dynamic response model of the surrounding rock-support system under impact loading was established. The dynamic response at the support end was investigated using the Newmark-
β average acceleration method and numerical calculation software. The effects of increasing support stiffness and changing rock stratum structure on the dynamic response of the support end under conventional support were analyzed. Under the same disturbance load and rock stratum model, the dynamic response and energy peak at the support end were compared among conventional support, energy-dissipating support, and energy-absorbing support. The results show that when the support stiffness is increased to 5 times the original value under conventional support, the peak displacement responses before and after the disturbance load decrease by 80% and 87%, respectively, and the peak acceleration responses decrease by 74% and 61%, respectively. Further increasing the support stiffness no longer leads to an obvious reduction in the dynamic response at the support end. After optimizing the rock stratum structure by keeping the siltstone stratum unchanged and dividing the coal seam mass into five equal parts, the peak displacement responses before and after the disturbance load decrease by 60% and 69%, respectively, and the peak acceleration responses decrease by 66% and 45%, respectively. Under the same conditions, compared with conventional support, the peak vibration energy at the support end decreases by 18% and 92% for energy-dissipating support and energy-absorbing support, respectively, with the dynamic response durations of 10.7 s and 8.9 s. Reasonably increasing support stiffness and optimizing the rock stratum structure can effectively reduce the displacement and acceleration amplitudes and weaken the dynamic response at the support end. Installing damping and energy-absorbing components in roadway support is conducive to dissipating and absorbing impact energy and quickly suppressing the vibration of the rock blocks at the support end. Therefore, high-strength energy-absorbing support with damping can be used to prevent and control rock burst.