Earthquake records on concrete dams in Japan : comparison with finite-element analyses

From 2014 to 2016, EDF was part of the cooperation between French (CFBR) and Japanese (JCOLD) committees on Large Dams occurred on the subject of dam’s behavior under earthquake. In Japan, seismic recordings have been conducted on existing dams and JCOLD released in 2014 an update of its databases of earthquake recordings on dams among them 135 gravity dams and 22 arch dams. The dynamic responses of gravity and arch dams are simulated by finite-element analyses using data recorded at the foundation and the responses are compared to the data recorded at sensor located at the dam’s crest. Comparisons between analyses and records confirm that the conventional massless foundation/added masses approaches with 5% concrete damping greatly overestimates the response of concrete dam, particularly in the case of gravity dams. The use of more advanced models taking into account the mass of the foundation, viscous-spring boundary input model and potential-based fluid finite elements with absorptive boundaries leads to more adequate values.