Dynamic damage and response characteristics of the tunnel by FEM modeling and field trials

The dynamic response characteristics of the tunnel and the stability of the surrounding rock are crucial to its safety of the tunnel. Combining the numerical simulation software and field measurement results, the change of peak particle vibration (PPV) and stress were analyzed, based on the longitudinal wave data from the acoustic tests, the blasting damage effects under the action of different blasting counts, including different locations in the deep part of the surrounding rock, were investigated. The results show that: (1) in the vertical direction of the tunnel, the PPV of the tunnel floor and tunnel sidewall is larger, the PPV of the tunnel top is the second, and the tunnel arch shoulder and arch foot is the smallest; (2) under the action of blasting, the stress concentration at the tunnel bottom and arch foot is easier, and the stress monitoring should be strengthened; (3) The depth of damage at different distances was 1.5 m and 3.0 m, respectively, and the depth of damage to the surrounding rock increased from 2.5 m to 4.0 m when the number of blasts was 10 and the number of blasts was 10.