Evaluation of Underwater Blast on Concrete Gravity Dams Using ThreeDimensional FiniteElement Model

Dams may undergo the air or underwater blast loading. An underwater explosion can cause significantly more damage to targets in water as compared to an explosion of the same magnitude in the air. It is well known that underwater explosions damage structures of dams by shockwaves and bubble pulsations. This paper studies the effect of the underwater explosion on a concrete gravity dam in different blast locations, with and without considering bubble pulsations. Concrete Damage Plasticity (CDP) is a model that can be used to characterize the constitutive behavior of concrete by introducing scalar damage variables. The results showed that damage was most visible when an explosion occurred in the middle of the reservoir. Damages were significantly higher in the case of bubble impulse dams. According to the results of the damage, bubble pulsation is an explosion in one of the main parts and includes part of blasts energy. Therefore, the amounts of displacement for cases with gas bubble effects were significantly higher than those with an explosion modeled only on the application of shockwaves. The existence of sediments and surface waves can be considered in further studies