Damage Evaluation of Tunnel Due to Internal Blast in Adjacent Tunnel

Tunneling is a branch of civil engineering that has experienced many changes over the time and even today the development of tunneling technology makes it increasingly powerful. The tunnel design, construction planning and the study of its behavior under different loading conditions involve many interdisciplinary aspects of geological, geotechnical and structural engineering. It is a complex mechanism of soil-structure interaction strongly influenced by the nature of the geological strata, the excavation process and lining technology. In purview of recent anti-social activities, underground tunnels especially, the urban metro tunnels are easy targets to create a chaos and disturb the harmony. Keeping this in mind, the present study focusses to understand the behavior and assess the damage incurred by Reinforced Concrete (RC) lining of the circular twin tunnels and the surrounding soil medium when subjected to internal blast load in one of the tunnels. The influence of different loading conditions, such as, the pillar width between the twin tunnels (varying from 1 to 3D, where D—diameter of tunnel), TNT weight (50–100 kg), RC lining thickness (275–350 mm), in terms of deformation on tunnel sidewalls and crown is determined. The twin tunnels and lining model are developed with the help of numerical modeling software Abaqus/CAE and the blast load (TNT Explosive) is generated by using CONWEP model.