Chapter

Perspectives on European Earthquake Engineering and Seismology

Volume 34 of the series Geotechnical, Geological and Earthquake Engineering pp 627-650

Open Access This content is freely available online to anyone, anywhere at any time.

Date:

Seismic Hazard and Seismic Design and Safety Aspects of Large Dam Projects

  • Martin WielandAffiliated withCommittee on Seismic Aspects of Dam Design, International Commission on Large Dams, c/o Poyry Switzerland Ltd. Email author 

Abstract

Earthquakes can affect large dam projects in many different ways. Usually, design engineers are focussing on ground shaking and neglect the other aspects. The May 12, 2008 Wenchuan earthquake has damaged 1803 dams and reservoirs. The widespread mass movements have caused substantial damage to dams and surface powerhouses in Sichuan province in China. The different features of the earthquake hazard are presented, the most important are ground shaking, faulting and mass movements. The basic requirement of any large dam is safety. Today, an integral dam safety concept is used, which includes (i) structural safety, (ii) dam safety monitoring, (iii) operational safety and maintenance, and (iv) emergency planning. The importance of these four safety elements is discussed. The long-term safety includes, first, the analysis of all hazards affecting the project, i.e. hazards from the natural environment, hazards from the man-made environment and project-specific and site-specific hazards. The role of the earthquake hazard on the seismic design and seismic safety of large dam projects are discussed as, today, the structural safety of large storage dams is often governed by the earthquake load case. The seismic design and performance criteria of dams and safety-relevant elements such as spillways and bottom outlets recommended by the seismic committee of the International Commission on Large Dams are presented. The conceptual and constructional requirements for the seismic design of concrete and embankment dams are given, which often are more important than the seismic design criteria that are used as a basis for dynamic analyses. Finally, the need and importance of periodic reviews of the seismic safety of existing dams is discussed.