Analysis of source and path of water inrush in karst tunnel based on the theory of groundwater flow system

Shuanglong Cave is a famous national scenic spot.The proposed Jinhua Mountain Tunnel is located about 12 km northeast of the Shuanglong Cave Scenic Area in Jinhua City, Zhejiang Province.The excavation of the Jinhua Mountain Tunnel may cause the karst water in Shuanglong Cave Scenic Area to be drained.At the same time, the tunnel may also be possiblely suffer the danger of karst water inrush.Based on the theory of groundwater flow system, combined with the survey results of hydrogeological conditions in the study area, the division of karst groundwater flow systems, the analysis of the geological structure of the key karst distribution areas at the exit of the tunnel, and the results of hydrogeochemical tests, the hydraulic connection between the two karst groundwater flow systems where the Shuanglong Cave and the tunnel site are located and the possibility of water inrush were analyzed.The results show that: if the tunnel exit section is exposed to the karst aquifer and drained, it will only affect the limit