ANALYSIS OF UNDERGROUND STRUCTURE UNDER BLAST LOADING

Abstract

Three-dimensional numerical simulations were used in this study to determine the behavior of a underground concrete structure under blast loads. Bomb attacks, which are currently common in various regions of the world, could also be the result of sabotage and terrorism. Explosions and bomb attacks cause a high-intensity, short-duration impulsive loading (shock) on structures in the immediate region of the blast. When concrete and steel are subjected to a blast, it is incredibly difficult to predict how they will behave. Using both experiments and numerical simulations, the modelling of material behavior has been comprehensively studied. The Johnson Cook Damage Plasticity model for ductile material was used to simulate the behavior of the reinforcing steel, while the concrete damage plasticity model and the Drucker-Pager Plasticity model were utilized to simulate the behavior of the concrete, sand, and rock, respectively. For concrete, sand, and rock, a 3D continuum element with lower integration was used. Steel reinforcement was done with a 3D truss element. The structure studied included a rock layer and a sand layer that served as a protective cover over the underground tunnel system. The rock cover is 6.5 m thick, the sand layer is 2 m thick, and the tunnel is 1.2 m thick. Blast loads on the overall structure has been discovered to be significant. The simulations were carried out using the Abaqus/Explicit 6.14 code, which is a Finite Element solver. The final findings of the analysis are expressed in terms of compression and tension damage, maximum primary stress, and Von-Mises stresses, taking into consideration a wide range of input conditions.