Effect of bubble pulse on concrete gravity dam subjected to underwater explosion: Centrifuge test and numerical simulation

The purpose of this study is to use small-scale centrifuge tests and numerical simulations to explore the effect of bubble pulse on concrete gravity dams subjected to underwater explosions. To the best of the authors' knowledge, there is still no systematic research focusing on this topic. In this study, five small-scale centrifuge tests previously performed were used. A numerical model was established based on the Coupled Lagrangian-Eulerian method and was validated by the centrifuge tests. Results revealed that the bubble pulse can introduce a secondary attack that can further destroy the dam structures on the base of the damage induced by the shock wave. Local responses of the dam were relevant to peak pressures of the shock wave and the bubble pulse, whereas global structural responses were dependent on their impulses. For a standoff distance greater than the maximum bubble radius, their impulses were close and thereby the induced global structural responses were comparable. For a standoff distance less than the maximum bubble radius, the impulse of the shock wave was remarkably higher than that of the bubble pulse, and thus the dam structures were destroyed by the shock wave before the bubble pulse arrived.