Integrated Seismic Risk Analysis for Earth Dams: Fid-Bau Portal

Integrated Seismic Risk Analysis for Earth Dams

M. K. Yegian / E. A. Marciano / V. G. Ghahraman

To evaluate the overall seismic risk damage to or failure of earth dams, an Integrated Seismic Risk Analysis procedure was developed. The analysis combines the probabilistic prediction of occurrence of seismic events with probabilistic prediction of the performance of a dam experiencing these events and provides estimates of seismic risk. The Seismic Hazard Analysis results were expressed in terms of joint occurrence of peak ground acceleration and earthquake magnitude or associated number of equivalent cycles. Furthermore, a probabilistic procedure for the calculation of permanent deformation of earth dams was developed in which the seismic event is characterized in terms of acceleration, number of cycles and predominant period of motion. The application of these procedures provides estimates of relative risks, which are useful in design and decision analysis, where trade-offs are made between the cost of increasing the seismic resistance and the risks associated with the consequences of seismic damage. In addition, risk-based safety evaluation enables identification of the most important parameters, assumptions, hypotheses and safety criterion affecting the evaluation of the safety of the dam and avoids compounding of conservatism.