Abstract
Results evaluated by dynamic analysis method will be changed according to the analytical models for coupled dam-foundation-reservoir system, the values of dynamic deformation properties of dam and foundation, the dynamic analysis program used, and so forth. Therefore, in order to realize a reliable evaluation for earthquake safety of existing dams, it is necessary to verify a validity of dynamic analysis procedure. If the actual earthquake motions are obtained by the seismological observations at existing dams, it becomes possible to make the reproduction analyses for actual earthquake behaviors of existing dams, and to prove an efficiency of dynamic analysis procedure based on the real earthquake phenomena. In order to establish an accurate and reliable evaluation for seismic safety of dams, I have developed a 3-D dynamic analysis method for coupled dam-joint-foundation-reservoir system, thus far. And I have been making the 3-D reproduction analyses for the actual earthquake behaviors of several existing dams. In this paper, the 3-D reproduction analyses in regard to the Tagokura Dam during the 2004 Niigataken-chuetsu Earthquake and the Ikehara Dam during the 1995 Hyogoken-nanbu Earthquake were described. And an efficiency and a meaning of the 3-D reproduction analyses was considered from the viewpoint of an effective utilization of earthquake observation data.
