Stability assessment of the Farrokhi earth embankment dam using the pseudo-static and deformation based methods

The behavior of earth dams has particular complexities against dynamic forces and its assessment requiresdetailed and scientific analysis. The Farrokhi earth dam is a heterogeneous type with vertical clay core, built 150 km away from Birjand and 41 km away from Qaen on the Farrokhi River. There are concernsregarding the stability of this dam in the event of a future severe earthquake especially because of itsplacement near the active faults of eastern Iran, a very active seismic area in the country. In this study, thepseudo-static analysis, sliding block model and Singh et al empirical relationships were adopted to evaluate safety of the Farrokhi dam against the design earthquake. Based on the findings of the present study, thestability of the Farrokhi earth dam is not guaranteed and as such, small to large size slope failures are expected especially in the upstream side. The pseudo-static analysis and the Singh et al empirical relationships revealed similar conclusions about the stability condition of this dam, while the sliding block method underestimated the earthquake related deformations.