Static and Dynamic Safety Evaluation of A Heightened Arch Dam Including Massed Foundation Effects

Abstract

DEZ dam is a double curvature arch dam built between 1959 and 1963. After more than 50 years of operation, the reservoir's storage capacity was reduced due to sedimentation, threatening its useful life and power intake. Several solutions were examined, and heightening the dam body was chosen as the most economical solution. Consequently, the seismic safety of the heightened structure was seen as indispensable. This study investigates the seismic safety of DEZ dam, considering the effects of heightening the dam body. Static loads and two levels of OBE and MCE earthquakes are applied to the finite element model of the dam-massed foundation-reservoir system. In static loadings, local stress concentration occurs in the heightened dam. Additionally, under the OBE earthquake, some limited damage is predicted, which is not problematic for dam safety. Finally, Under MCE records, some cracked regions are developed. Still, the model does not show general instability, and so, the cracked areas do not lead to the release of the reservoir.