Application of CSAMT monitoring method and observational construction management to mountain tunnel

The CSAMT (controlled source audio magneto-telluric) method was applied to estimate the condition of the ground with fracture zones and heavily water-bearing zones for tunneling. The analyzed distributions of porosity and water content by volume resulted in good agreement with the results of actual ground condition through construction. Thus, the applicability of the method was confirmed. For the design of a T-shaped tunnel, three-dimensional finite element analysis was applied using the monitoring data of the ground. The tunnel was constructed by an observational method based on the data measured during construction. As a result, the validity of the design was confirmed by grasping the ground behavior at the intersection of the tunnels.