云南省元-磨公路大风垭口隧道施工地质灾害分析

大风垭口隧道是云南省正在建设的元—磨高速公路控制性工程，也是云南省在建的最长公路隧道。该隧道施工过程中出现的地质灾害类型主要有涌水、崩塌、洞口滑坡、岩溶、突泥等，对施工造成了很大的影响，影响了施工进度，增加了工程投资，并对工程的稳定性有潜在的威胁。这些地质灾害的发生与地层岩性、岩体结构、地质构造、水文及人为因素有关。塌方主要发生在碳质板岩中，涌水在各种岩石中均有发生。相对挤压带和松弛带以近等间距相间出现是大风垭口隧道围岩地质构造的一个显著特征，而施工中的地质灾害主要出现在构造松弛带中。隧道开挖的实际地质情况与工程地质勘探成果有较大的出入则是灾害发生的人为因素。

Geological hazards during the construction of Dafengyakou Tunnel in Yunnan Province

The geological hazards occurred during the construction of Dafengyakou tunnel in Yunnan province include water\|gushing,collapse,landslide,sinkhole and mud\|piping.Their presence is due to the stratigraphy and rock property,rockmass structure,geological structure,hydrogeology and technique of excavation.Collapse occurred mainly in the carbonaceous slate, while water\|gushing happened in all kinds of rocks.The alternate of relatively compressional and extensional zones is a remarkable feature of the geological structure and the geological hazards predominantly occurred in the extensional zones.It is found that the incorrect explanation of gite investigation results and insufficient site investigation also resulted the formation of geological hazards.