Blast-induced vibration attenuation characteristics of wave-absorbing anchorage in deep-buried tunnels

During the construction of deep-buried tunnels, dynamic disturbances may adversely affect surrounding rock stability, while research on vibration control measures and their influence on wave attenuation remains limited. In this study, a wave-absorbing anchorage composed of wave-absorbing anchoring mortar and rock bolts was employed to conduct field tests on wave attenuation in a deep-buried tunnel. The attenuation characteristics of blasting vibration intensity were analyzed for a single wave-absorbing anchorage (single-anchorage) and for the region between two adjacent wave-absorbing anchorages (inter-anchorage). Both the single-anchorage and inter-anchorage configurations reduced vibration intensity in the axial direction by 28.7% and 21.8%, respectively, and in the radial direction by 10.8% and 18.9%, respectively, whereas a slight increase was observed in the tangential direction. Subsequently, numerical simulations were performed to investigate the variations in vibration velocity and stress before and after stress waves passed through the wave-absorbing anchorage. The reflection and refraction of stress waves upon encountering the anchorage are important factors in the attenuation and the redistribution of three-directional vibration components. Based on these findings, the wave-absorbing performance of group-anchorage support was further evaluated through numerical simulations. The offset-densified group-anchorage exhibited stronger attenuation capability than the conventional rectangular group-anchorage. This study provides a reference for the prevention and control of hazards induced by dynamic disturbances in deep-buried underground engineering.