A study on damage prediction of a concrete gravity dam under underwater non-contact explosive loads

Dams are important water-retaining structures. Their safety directly affects the lives and properties of downstream people. Once a dam break occurs, the consequences will be disastrous. Based on the Euler and Lagrange fluid-solid coupling algorithm, underwater non-contact explosion damage of a concrete gravity dam was studied by using the LSDYNA software in this paper. High strain rate effect of the concrete was considered. The relationship between underwater non-contact explosive loads and the damage degree of the dam was discussed, which is affected by initiation depths, initiation distances, water level in front of the dam, and explosive equivalent. The prediction curve of dam damage degree was fit. The study shows that the detonation depth, detonation distance, and the degree of water level in front of the dam are all important factors that affect the anti-blast performance of the dam. The damage location on the upstream surface moves to the bottom of the dam as the initiation depth increases. The greater the detonation depth, the more difficult to form penetrating damage. Closed explosions cause more serious damage to the dam. Low-water level explosions can effectively reduce the damage of the dam and improve the dam's anti-blast ability. When a war occurs, some measures should be taken to minimize the impact damage of the dam, such as emptying the reservoir water in advance, preventing the bomb from exploding in water, or preventing the bomb from approaching the dam. The results can predict the damage degree of the dam subjected to underwater non-contact explosive loads, providing a certain basis for the government's decision. © 2022, Editorial Office of Journal of Vibration and Shock. All right reserved.