Changes to Expect in Seismic Safety Assessment of Large Storage Dams in Future

Since the 1930s, when the pseudostatic seismic analysis methods for concrete and embankment dams were introduced, the following developments have taken place: (i) change from pseudostatic to dynamic seismic analysis of dams, (ii) change from the representation of the earthquake ground shaking by a seismic coefficient to safety evaluation earthquake ground motion parameters, (iii) change from single ground shaking hazard to multiple seismic hazards including mass movements, and faulting, and (iv) change from safety factor concept to rational seismic performance criteria, characterized by dam deformations. There are still considerable uncertainties about the behaviour of a dam under very strong ground shaking. The following topics are discussed that need further attention: inelastic earthquake behaviour of dams under strong ground shaking; seismic strengthening of existing dams; short-term behaviour of mass concrete, RCC and rockfill materials; seismic design of hydro-mechanical and electro-mechanical equipment; abutment stability of arch dams during earthquakes; seismic behaviour of asphalt core rockfill dams and other new types of dams; seismic safety of tailings dams during operation and longtime storage phase, and seismic design and performance criteria. These seismic safety aspects of dams are discussed in the paper.