Calculation Method for Water Inflow of Typical Fault Zone in Volcanic Rock Tunnel:Case Study of Qingyunshan Tunnel

With an example of a volcanic surrounding rocks tunnel in Fujian Province,the characters of volcanic aquifer structure and tunnel water inflow have been summarized,and then various methods including the rainfall infiltration method,analytical methods and numerical method are used to calculate the water inflow along the typical fault zones in tunnels.Compared with observed data,the suitability of those methods is evaluated.The results show that,the water inflow along tunnel in a volcanic surrounding rock tunnel is characterized by the pattern of multi-segments inflow controlled by fault.Most traditional analytical methods based on hydrodynamic theory are more suitable for determination of tunnel influx than the rainfall infiltration method and the tritium isotope approach.Numerical methods show their advantages in calculation of initial tunnel inflow by characterizing the heterogeneity of fault zone and complex domain boundary.However,the accuracy of calculated tunnel inflow highly depends on the hydrogeological survey and the description of aquifer parameters.