A Novel Wave-Absorbing Support System for Mitigating Rock Burst in Deep-Buried Hard Rock Tunnels
摘要
Numerous deep rock engineering projects, such as the deep underground laboratory and deep-buried tunnel, have demonstrated through on-site monitoring that stress waves can induce rock bursts in the surrounding rock mass at a certain distance from the excavation face. Drawing on the evolutionary process of rock bursts triggered by blasting disturbances in deep engineering projects, a novel wave-absorbing support system method has been proposed to attenuate the propagation of stress waves. By utilizing anchorages with wave-absorbing properties, a fin-shaped layer is formed within the surrounding rock mass through grouting and shotcrete processes. The analysis of stress wave transmission and reflection at the interface has revealed that reducing the wave impedance of the support material can effectively weaken stress wave disturbances within the rock mass. Extensive material selection and dynamic testing have led to the development of a high-strength, low wave impedance wave-absorbing material with a strength exceeding 20 MPa. The installation of wave-absorbing rock bolts within a certain deep-buried railway tunnel, coupled with the arrangement of blast-induced vibration monitoring devices inside the surrounding rock mass, has enabled the measurement of vibration velocity as the blast-induced waves pass through the support material. The experimental results indicate a significant reduction in vibration peak amplitudes, demonstrating the capability of the wave-absorbing support system to attenuate vibration waves.