Evaluation of Earth Dam Behavior against Earthquake with respect to Dam Height and Constitutive Model of Dam Materials

In spite of the fact that the effect of earthquake on earth dams has been widely studied during the past decades, the complicated behavior of such earth structures against different seismological characteristics is still unknown. Such ambiguities necessitate more accurate studies using more comprehensive computation tools to achieve new results describing the behavior of such structures subjected to earthquake loading. In the present study, the simple soil model of elastic, perfectly plastic (based on the Mohr-Coulomb criterion), and Rayleigh damping criterion have been adopted for the soil. First, the numerical model employed was verified by dynamic analysis of real cases such as “Long Valley” and “santa Felecia” earth dams. The computational results were then compared with real recorded data or with those reported by other researchers. In addition to evaluating seismic stability of earth dams, their seismic stability was verified using pseudo-static analyses. Therefore, the “Carsington” dam was analyzed to verify the results of pseudo-static analyses and to check the results of FLAC software in calculating the pseudo-static factor of safety. The values of calculated factors of safety in the present study are in good agreement with the published results in the literature. Furthermore, the failure behavior revealed in the analysis shows the ability of FLAC software in defining the failure surface. In the main part of the analyses, a parametric study was conducted for different selected conditions and specially the effect of dam height and the optimum size of crest width were investigated. The results are presented in relevant diagrams.