Numerical study on underground structures subjected to shock loading

This paper presents a numerical investigation on shock response of underground structures made of fibre reinforced composite material. A finite element model is developed for determining the shock response of the structure including soil-structure interactions. Commercially available software ABAQUS is used for the finite element model and computations. Circular, horseshoe and square cross-sections of the underground structures are considered for the analysis and design against the air blast of 500 kT TNT at a distance of 1 mile. Equivalent of TNT yield value the pressures and time histories are generated and accordingly blast parameters are obtained. The mechanical properties of steel fibre composite material used in the study are determined based on laboratory tests. The soil-structure interaction effects are implemented through spring and dashpot systems at the boundary regions. Various responses like displacements, von Mises stresses and strain energies obtained from the numerical analysis are reported.