高地应力水平层状硬岩隧道岩爆分级与防控技术研究

Study on Rock Burst Classification and Prevention and Control Technology of Hard Rock Tunnel with High Ground Stress Level

本文依托乐汉高速大峡谷隧道,总结分析了高地应力水平层岩爆的特征并提出了岩爆分级标准。在岩爆分级的基础上,提出了针对不同岩爆等级的处置措施。现场实践结果表明,对于弱岩爆可以采用全断面法开挖,降低扰动次数。对于中~强岩爆段,宜采取短进尺分部开挖,降低爆破对围岩的一次性扰动,同时采取应力释放孔、应力解除爆破孔等辅助措施提前释放围岩应力。

Based on the Grand Canyon Tunnel of Lehan expressway,this study summarized and analyzed the characteristics of rock bursts occurred in layered rockmass under high geo-stress condition and proposed a rockburst classification standard.On the basis of rock burst classification,disposal measures for different rock burst levels have been proposed.The on-site practice results indicate that for weak rock bursts,the full section excavation method can be used to reduce the number of disturbances.For medium to strong rock burst sections,it is advisable to adopt short footage step-by-step excavation to reduce one-time disturbance of the surrounding rock caused by blasting.At the same time,auxiliary measures such as stress relief holes and stress relief blasting holes should be taken to release the stress of the surrounding rock in advance.