Influence of Burial Depth of Soil on Reinforced Concrete Tunnel Against the Impact and Blast Loading

Underground Tunnels are a necessary segment of the present infrastructure system. The tunnel system has become an important part of the present infrastructure all over the world. With increasing use and popularity, the underground tunnels are always prone to natural and man-made attacks. Therefore, an attempt has been made to study the response of underground tunnels against impact loading as well as blast loading for different burial depths 5, 10, and 15 cm of soil. This paper highlights the influence of burial depth over the tunnel against impact loading with the mass of impactor 104 kg. Also, the paper highlights the influence of burial depth over the tunnel against blast loading of varying masses of TNT. The experiments were performed on the underground tunnels with different burial depths 5, 10, and 15 cm of soil and measured in terms of the impact force as well as deformed profile. The simulations were conducted on a semi-circular shaped reinforced concrete tunnel with 0.5 m center to center diameter, 1.2 m of length, and 0.05 m of thickness using ABAQUS/CAE Explicit software. The constitutive behavior of concrete, steel reinforcement, and soil element are defined by using the Concrete Damaged Plasticity model, Johnson–Cook Plasticity model, and Drucker-Prager model, respectively. The simulation findings were compared to the experimental results and they were found in good agreement. The major conclusions were drawn based on the impact as well as blast loading on the underground tunnels with varying burial depths.