Impacts of bench blasting vibration on the stability of the surrounding rock masses of roadways

In the process of open-pit and underground mining, the seismic wave generated by open-pit blasting can influence the stability of the surrounding rock masses on a roadway. It is easy to destabilize the surrounding rock, which seriously affects the stability of the roadway and the safety of the underground mining operation. The effects of the blasting vibration on the surrounding rock of the roadway are difficult to obtain with field data and pure theoretical research is relatively difficult to conduct. In this study, we used China's Anjialing Coal Mine and its combined open-underground mining as the research site and used numerical simulations and field observations to analyze the roadway lining, the surrounding loose rock, the anchor, and the stability of the surrounding loose rock before and after blasting to evaluate the effects of the blasting vibration. In addition, the stress transfer of the anchor and lining before and after blasting is analyzed and the performance and safety of the anchor and lining are evaluated in order to determine the mode of propagation of the seismic wave in open pit blasting. The results show that the vibration velocity at each measuring point is less than 15 cm/s and that the vibration peak of each measuring point is attenuated with an increase in the distance from the point to the explosion source. The blasting vibration can affect the surrounding rock to various degrees in a specific range and the redistribution of the surrounding rock does not result in an increase in the surrounding loose rock. The influence of blasting on the stress of the anchor decreases with the distance from the blasting source. The results of this study can predict and control the abrupt structural and local failure caused by blasting to ensure the stability of the underground structure and the surrounding rock and to maintain the safety of the construction process.