| During the Iwate-Miyagi Nairiku Earthquake in 2008, large settlement without sliding was observed at Isawa dam, an earth core rockfill dam with a height of 132m under construction, located in Iwate Prefecture, Japan. Dam height at the time of the earthquake was about 84m. In this study,we conducted reproduction analysis for deformation behaviour during the earthquake. For the analysis, we conducted dynamic laboratory tests for construction materials and evaluated differences of dynamic properties due to the saturated or unsaturated conditions. We conducted the sliding deformation analysis using Newmark method. We calculated settlement induced by the earthquake motion based on the cumulative damage theory and evaluated differences of behaviour due to saturated or unsaturated conditions. Reproducibility was confirmed by comparing the analytical results and the observed differential settlement data. We found that the reproducibility of the shaking down settlement was fine in the case of using the dynamic strength properties of saturated conditions in core material and those of unsaturated conditions in filter and rock materials. Results of the sliding deformation analysis using Newmark method was not generated sliding displacement. It was the same as the actual phenomenon of the dam during the earthquake. |
