Operational Safety of Dams and Hydropower Installations: Fid-Bau Portal

Operational Safety of Dams and Hydropower Installations

Ascila, Romanas / Hartford, Desmond N. D. / Zielinski, P. Andy

This paper discusses simulation approaches to understanding the systems operations of dams and hydropower plants, and provides practical examples from current practice in Canada and Sweden. Dams and hydropower installations are complex structures or systems of interest comprising geotechnical, structural, mechanical, electric, and other subsystems, such as gates, control equipment, and operators. A dam system—in contrast to just the dam—comprises the embankment of the dam along with the various waterways past the dam, and usually with accompanying mechanical and electrical equipment for on-site operational control. Current engineering approaches to dam safety are mostly based on probabilistic risk analysis (PRA) of the geotechnical aspects of the dam (e.g., slope stability under seismic loads, internal piping, overtopping erosion, abutment stability, etc.). PRA primarily address the capability of a dam to withstand loads, such as the demand caused by the design flood and the spillway’s capacity to pass that flood, or the demand caused by the design earthquake and the dam’s capacity to withstand resulting ground shaking. In contrast, experience has shown that many dam failures and perhaps the majority of dam incidents do not result from extreme geophysical loads, but rather from operational events. These incidents and failures occur because an unusual combination of reasonably common events occurs, and that unusual combination of events has an undesirable outcome.