Techniques to safeguard the underground tunnels against surface blast load

Due to the growth of underground tunnels, the safety of structures under blast loading is a major threat. Therefore, this paper focused on various techniques such as tunnel burial depth, tunnel shape, tunnel lining materials and varying the location of the blast source to safeguard underground tunnels against blast load using numerical analysis. The behaviour of concrete, reinforcement steel and the soil were incorporated by using the different constitutive model available in ABAQUS v. 2020. The predicted results were compared with the experimental results available in literature and found in close agreement. It is concluded that the layering of soil filling and depth of the burial of the tunnel found to be most important in case of external blast, whereas the stress bearing capacity of the concrete found to be important in case of internal blast. It is also concluded that the circular shape tunnel is one of the best performing tunnels.