Dynamic response of tunnels due to surface explosions using nonlinear numerical modelling
Ali Adnan Khadra 1, Hala Hasan 1, Turki Tabak 2
1 Higher Institute for Earthquake Studies and Research, Damascus University, Syria
2 Scientific Studies and Research Center of Aleppo, Syria
Destructive blasts can have strong effects on buried facilities. This paper evaluates the dynamic response of a reinforced concrete tunnel using one complete model, which includes an explosion, the shock wave propagation through the soil, the interaction of the soil with the tunnel lining, and the tunnel response itself. The simulations were performed using the ABAQUS/Explicit finite element package. For the explosion the Jones-Wilkens-Lee equation is used. The soil behaviour is captured with the elastoplastic Drucker-Prager Cap model, the concrete is described by the Concrete Damaged Plasticity model and the reinforcement is modelled as an elasto-plastic material. The contact surface between the soil and the tunnel uses Mohr-Coulomb friction that allows for sliding, separating, and rebounding of the tunnel's surface to the surrounding soil. Varied parameters are the reinforcement ratio and the construction depth. Increasing the reinforcement ratio reduces the, damage to the tunnel lining and with a suitable construction depth, the tunnel can be relatively safe from failure.
Key words: Surface explosion, numerical simulation, dynamic response, soil-structure interaction, tunnel