Seismic Safety Evaluation of Concrete Gravity Dams Based on Performance Criteria (Case Study of Hygher Dam)

In this paper, the seismic performance safety of a concrete gravity dam (Hygher dam) located in Fars Province, Iran, has been evaluated. Probable levels of seismic damages of Hygher dam induced by three levels of ground motions (DBE, MDE and MCE) have been quantitatively estimated according to the USACE guidelines. The methodology is based on the stress demand-capacity ratio (DCR) and the cumulative inelastic duration as two performance indices. Based on the EAGD computer code linear analyses results, it is concluded that the response of the dam at the DBE level (0.34g) will exhibit either no damage or at most minor damages. At the MDE and MCE levels (0.42g and 0.55g), some tensile cracking will occur, but its level is considered acceptable with no possibility of total collapse. According to the proposed performance criteria, the selected ground motions did not produce significant nonlinear deformation in this dam, and so the said guideline did not require nonlinear analysis to be performed.