Introduction to Armoring Embankment Dams and Earth-Cut Spillways with ACBs

 Introduction to Armoring Embankment Dams and Earth-Cut Spillways with ACBs

Over the past 23 years numerous embankment dams and earth-cut spillways in the United States have been armored with Articulating Concrete Blocks (ACBs) to provide overtopping protection and to extend the life of the structures.  With the current focus on evaluating and rehabilitating dams throughout the United States to pass increased design flows, the use of this construction technology has become popular.  As a result, some ACB manufacturers have made significant investments in research and development of their concrete block systems to evaluate and improve their performance for use on embankment dams and earth-cut spillways, provide design data for designers, and develop more economical embankment armoring solutions.  In addition to established ACB manufacturers, researchers from Colorado State University, the USDA Bureau of Reclamation and the U.S. Army Corps of Engineers have designed, tested, and patented ACB systems for use on embankment dams, spillways and channels. Several dams and spillways armored with ACBs have been overtopped and performed satisfactorily with overtopping flow depths and velocities approaching 4 feet and 30 feet per second, respectively. Over the same period, at least one known ACB overtopping application has failed.  Much has been learned about what works and what does not work.

This webinar will be presented in two parts.  In Part 1, Dr. Chris Thornton will focus on ACB theory and will provide a brief history of the origins of ACB systems, discuss their development, and summarize the physical model investigations that have been completed to date to assess the performance and stability of various ACB systems.  Dr. Thornton will also present the latest approach for analyzing and interpreting the test data for use in design applications.  In Part 2, Paul Schweiger will focus on ACB applications and provide a summary of the first applications of ACBs for dam embankment overtopping and spillway armoring, present performance information on ACB dam armoring projects that have experienced overtopping flows, and discuss lessons learned from these and other projects.  

The purpose of this webinar is to provide practitioners with an introduction to the application of ACBs for use in armoring embankment dams and spillways.