川藏交通廊道雅林段水文地质结构控制的水热循环及隧道热害特征

Characteristics of Geothermal Cycle and Tunnel Geothermal Disaster Controlled by Hydrogeological Structure in Ya’an to Linzhi Section of Sichuan-Tibet Traffic Corridor

川西藏东地区水热体系空间分布与川藏交通廊道布局关系的特殊性,使得隧道难以回避复杂多样的水热灾害.为系统分析工程面临的热害问题,对控制水热循环的水文地质结构进行辨识,辅以地球化学特征、钻孔温深关系解析,分析隧道穿越地热系统时可能遭遇热害的类型及灾变特征.活动性深大断裂与大型褶皱为区内重要控热构造,结合次级断裂、岩石富水性、热水出露特征,梳理出7类控制水热循环的水文地质结构;结合隧道与上述结构的空间关系、水热特征影响要素归纳出两大类、13小类的热害类型.典型案例分析显示康定1#隧道出口段、拉月隧道中段分别穿越折多塘温泉、拉月温泉水热系统排泄区,两段可能遭遇高温高压、突发性涌突水灾害.

Due to the particular relationship between the spatial distribution of hydrothermal systems and the layout of SichuanTibet traffic corridor,it is difficult for tunnels to avoid complex hydrothermal disaster.In order to systematically analyze the geothermal disasters which the tunnels possibly meet with,basing on the hydrogeological structure,geochemistry and relationship between earth temperature and depth,in this paper it analyzes the types and characteristics of hydrothermal disasters of SichuanTibet traffic corridor tunnels.Active,deeply buried faults,and large fold belts are important geological structures controlling the geothermal systems.Basing on hydrogeological structures,sub-faults,storage characteristics of groundwater in rocks,and outcropping characteristics of geothermal water,in this paper it concludes seven hydrological constructions of geothermal water circulation.Considering spatial relationship between tunnels and these hydrogeological structures,and factors influencing hydrothermal characteristics,two types and thirteen sub-types of geothermal disasters are concluded.The exit part of Kangding 1#tunnel and middle part of Layue tunnel pass through hydrothermal systems of Zheduotang warm spring and Layue warm spring respectively,these two parts may encounter geothermal disasters with high temperature and high pressure suddenly.