| "It is predicted that several strong earthquakes such as Tokai Earthquake, Miyagi-oki Earthquake will occur in Japan in the near future. So, it is increasingly becoming important to evaluate seismic performance of dams against Level-2 Earthquake motions that is the largest of ground motions estimated to occur in the future at each dam site. The Ministry of Land, Infrastructure and Transport is considering the method of evaluating the seismic performance of dam against Level-2 Earthquake motions in cooperation with PWRI and is now summarizing its findings to propose the guidelines. The seismic performance that the dam must keep against Level-2 Earthquake motions is to maintain the function that the dam stores water at least. It is necessary to judge whether or not a dam will be able to keep the function of storing water through the numerical analysis considering the damage to the dam. In the case of a concrete dam, it is necessary to consider the damage by the tensile crack generated in the dam body. Many researches concerning the methods of evaluating the tensile crack generated in a concrete dam body have been carried out. It is difficult to estimate the locations of the crack occurrence in the concrete gravity dam body in advance during large earthquakes. So we have conducted research on the method of evaluating seismic performance of concrete gravity dams using the smeared crack model that does not require the set of the locations of the crack occurrence in advance. In this report, the crack progress analysis for a concrete gravity dam using the smeared crack model was performed and the effect of the dam shape and the ground motion strength on the degree of crack damage to the concrete gravity dam was studied." |
