This is a standard two-dimensional model of a tunnel, where the parameters of the tunnel cavity are set to the air medium. Accordingly, the P-wave velocity, S-wave velocity, and density are set to: 340m/s, 0m/s, and 120kg/m3, respectively. The model size is 80 grid points in the vertical direction and 200 grid points in the horizontal direction. The tunnel size is set with a vertical rectangular structure located 40m in front of the tunnel face (at 120m on the X-axis).