Assessment of Damage in Concrete Tunnels under Internal and Surrounding Explosions

Concrete tunnels, as key elements of transportation infrastructure and critical facilities, are subjected to atypical loads such as explosions and surrounding pressures. In this study, the dynamic behavior of a buried concrete tunnel under an explosive load equivalent to ۵۰ kg of TNT and three different lateral loading conditions was investigated. In the first scenario, only the explosive load was applied to the tunnel. In the second scenario, in addition to the explosion, a uniform lateral pressure of ۶۰ MPa was applied to the tunnel lining. Numerical modeling was conducted using ABAQUS, considering the nonlinear behavior of the materials and full tunnel-soil interaction. The results indicate that increasing lateral load intensifies stress concentrations and induces localized deformations at the tunnel crown. Damage concentration was primarily observed in the upper section of the tunnel, highlighting the vulnerability of these areas under combined loading. The findings of this study can serve as a basis for optimal design and strengthening of buried concrete tunnels against severe and simultaneous loading conditions.

کلیدواژه ها:

Concrete tunnels ، explosive load ، stress concentration