Review on seismic aspects of embankment dams |
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학술지명 ICOLD 26th International Congress on Large Dams
저자 박동순
발표일 2018-07-05
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Seismic aspects of embankment dams are an important issue both for new dam design and seismic safety of existing dams. In this paper, a comprehensive review was performed about seismic aspects of embankment dams mainly focusing on (1) the important seismic parameters, (2) observational consequences of strong shaking, and (3) numerical and experimental study result of seismic response. Among various parameters, one of the predominant parameter to affect seismic response is fundamental period and its proximity to dominant frequency content. Another important finding is the counteractive effect between stiffness inhomogeneity induced amplification of motion and material nonlinearity induced suppression of unfavorable effect. Other multi-influencing parameters also need to be accounted for such as 3D canyon effect, reservoir water level, the directivity of motion, and dam-foundation interaction. Based on observation from case histories of dams subjected to strong shaking, well-engineered embankment dams are typically resistant to extremely large shaking while a less compacted or liquefiable layer is attributed to substantial damage for a few cases. Numerical analyses with sophisticated dynamic constitutive models and novel experimental approach including dynamic centrifuge modeling have been in great progress to reasonably estimate seismic response for lack of case histories. Substantially large earthquakes leave new findings each time, and serves as the important improvements for seismic design and evaluation of embankment dams. |