关键词: 隧道, 超前探测, 不良地质, 岩溶

Abstract: This paper presents a case history of the advanced detection of hazards in the tunnel excavations in potential adverse geological conditions of surrounding mas of Enshi, Hubei Province. A typical fractured surrounding rock mass with soft mudstone strata section of tunnel between stations YK30 + 890 and 790 was used as an study example, the actual locations karst rock cavities in this range were predicted by using the combination of transient electromagnetic and geological radar. Firstly, the low electrical resistance anomalous zone was identified using the transient electromagnetic method, and the exact range was detected using the ground penetrating radar. During the tunnel excavation process, a deeper borehole was used to verify the broken rock mass zone. The surrounding rock geology exposed by the tunnel site excavation validated the correctness of the advance geological prediction results. Based on the advance geological prediction results, short footage method and weak blasting construction technical measures ensured the stability of the surrounding rock mass, and the research results can provide reference for the construction of similar tunnels with unfavorable geology. 

Key words: Tunnel Excavations, Advanced Detection, Unfavorable Geologic Conditions, Karst