Numerical Models for Seismic Evaluation of Concrete Dams

This report critically evaluates the process of seismic safety assessment of concrete dams using state of the practice numerical models. It highlights fundamental characteristics and assumptions of different solution approaches and describes the fundamental concepts behind the mathematical formulations and corresponding solutions. The report emphasizes that numerical modeling of the seismic response of dams is not just a computation of deformations and stresses; it is rather a tool for assessment of the performance, identification and appraisal of potential failure modes, and determination of available or lack of margin of safety. For these reasons numerical modeling must be formulated to capture the correct structural conditions and load path, to model failure mechanisms that control stability of the dam, to accurately account for interaction effects that impact the results, and to select and apply seismic input that are representative of the earthquake ground motions expected at the dam site. The report was prepared by a subcommittee of the Committee on Earthquakes, comprising Bruce Brand and Yusof Ghanaat. George Horowitz assisted in editing the report. Other committee members reviewed and commented on it. USSD Committee on Earthquakes: Joseph L. Ehasz, Chairman; Donald H. Babbitt, Vice Chairman; John A. Barneich; Moshen Beikae; Bruce Brand; Gilles Bureau; Yusof Ghanaat; George F. Horowitz; Peter J. Hradilek; C. Michael Knarr; Richard W. Kramer; C. Eric Lindvall; Faiz I. Makdisi; Enrique E. Matheu; Larry K. Nuss; Warren J. Paul; Mark G. Schultz; John C. Stoessel.