Evaluation of base damage and stability of concrete gravity dam subjected to underwater explosion

Social infrastructures such as dam are likely to be exposed to high risks of terrorist and military attacks, leading to the increasing attentions on their vulnerability and catastrophic consequences under such events. Through a coupled numerical model, this paper aims to evaluate the sliding stability of concrete gravity dam along the dam base under various explosion scenarios, with the foundation lithology taken into consideration. The numerical results revealed that the foundation lithology has a significant influence on the shock wave propagation and the base damage of the concrete gravity dam when subjected to underwater explosion. The damage mechanism of dam base is dominated by the dam-foundation interaction under explosion. A model was then proposed to quantify blast-induced cracks adjacent to the dam base using the crack penetration ratio as a key parameter. The rigid body limit equilibrium method was finally deployed to assess the corresponding stability of concrete gravity dam with different types of foundation lithology. © 2022 Published by Elsevier Ltd on behalf of Institution of Structural Engineers.