ABSTRACT
In recent years, frequent occurrence of terrorist attacks using explosives has become a serious threat to the society. Public transit system has been the main target in the past. In the light of such unfortunate events, present investigation is focused on series of three-dimensional numerical simulations of underwater tunnel subjected to blast using LS-DYNA®. Herein, dynamic response of an underwater tunnel, with a circular cross-section, under internal explosion is carried out using Multi-Material Arbitrary Lagrangian Eulerian (MM-ALE) method. Sensitivity analysis is conducted to understand the variation in thickness of tunnel lining and weight of explosive. Significant deformation is observed with increase in the charge weight but it decreases when the lining thickness is increased. A foam lining is introduced as an intervening layer to sufficiently absorb the shock energy from the explosion. Numerical simulations are performed to determine the optimum thickness of foam lining that can effectively protect the structure.
