investigating concrete arch dam behavior under underwater explosion (case study:karun4 dam)

Studying the responses of dams to explosion-induced loads and evaluating their overall safety under such loads is highly significant regarding the strategic importance of dams. the present study investigates tnt-induced wave effects on the karun-4 dam in iran. for this purpose, dynamic analyses were carried out on the dam reservoir and foundation system via the finite element method (fem) in abaqus. the conwep theory allows the imposition of pressure loading caused by an explosion in the air. the reservoir was considered empty, and then three different heights of 225, 115, and 5 m were analyzed. the failure explosive weights of the three heights were calculated by trial and error. analyses were performed with 1000, 1200, and 1300 kg of tnt for the height of 225 m, 1900, 1950, and 2000 kg of tnt for the height of 115, and 1800, 1900, and 2000 kg of tnt for the height of 5 m. it was observed that the dam failed at loads of 1300, 2000, and 2000 kg of tnt when the explosion occurred at 225, 115, and 5 m, respectively. the analyses were performed based on these loads. the results indicated that the reservoir water level had a negligible effect on the arch dam’s failure blast load. moreover, analysis results of the dam-reservoir-foundation system in filled-up and empty reservoir cases suggest that the failure explosive loads of filled-up and empty reservoir dams do not significantly differ, and the failure explosive load of the filled-up case is slightly lower than that of the empty case. for example, at an explosion height of 225 m, the failure load of the filled-up reservoir case was derived to be 1500 kg of tnt, while that of the empty reservoir case was obtained to be 1300 kg of tnt.