Introduction to Concrete Gravity Dams: On-Demand

Speaker: Robert A. Kline, Jr., P.E., Vice President, Gannett Fleming, Inc.

PDHs: This webinar is eligible for 2 PDH credits. 

With the development in Europe in the later 1800s of a rational method for evaluating structural stability combined with practical experience, U.S. engineers gained greater confidence in increasing the structural height and loadings on masonry dams, as they were known then. This led to record setting heights in the U.S. for several gravity dams built for water supply purposes for major U.S. cities.

As records were being set, a few dramatic concrete gravity dam failures occurred which sparked wide debate concerning whether or not rational methods adequately accounted for various destabilizing external forces acting on a gravity dam. Many practicing engineers agreed that although estimates and likely ranges can be assigned to these forces, for some, exact values are indeterminate. Recognition was also given to the variable nature of material strength properties. This led to the adoption of the use of safety factors to better account for the indeterminate and variable nature of such factors.

Since many U.S. gravity dams in service today were constructed decades ago while design practices were still evolving, historical background for design and construction practices will be presented to provide today’s practitioners with a better understanding of potential vulnerabilities in these structures. Select noteworthy gravity dam failures will be presented as well with an emphasis on lessons learned from these failures.