The failure of a dam during an earthquake can produce immeasurable losses of life and property. In addition, serious damages even without failure can have severe economic consequences. To prevent such serious damages, it is required to soundly evaluate seismic performance of dams. Many dams have already constructed and operated, so the seismic performance evaluation has to adopt not only new planning dams, but also existing dams. The seismic performance evaluation of existing dams in Korea has been recently carried out by engineers and government-related organizations.
The seismic performance of a dam is evaluated by “Guideline of Seismic Performance Evaluation for Existing Dams” revised in 2004 (KISTEC, 2004). The safety factor for liquefaction and slope stability, and earthquake-induced permanent deformation are evaluated by this guideline. In the case of evaluating earthquake-induced permanent deformation, 1% of dam height is used as the allowable permanent settlement. However, there is no assessment whether this criterion is reliable although it has been used for many years. Therefore, it is needed to assess the validity of the 1% criterion to evaluate seismic dam performance reliably.
In this study, three methods are used to assess the criterion for earthquake-induced permanent deformation: dynamic centrifuge tests, numerical analyses and case studies. The result from each method was compared with the 1% criterion for validation study.
Firstly, dynamic centrifuge tests of earth-core rockfill dam (ECRD) and concrete-faced rockfill dam (CFRD) models were carried out to investigate their seismic behaviors when subjected to earthquake loadings. The earthquake-induced deformation, the characteristic of acceleration amplification and the earthquake-induced stress increments in CFRD facing were measured by various transduced. From the obtained test results, it was found that seismic behaviors of rockfill dams could reliably investigated by dynamic centrifuge tes...