International Workshop on Seismic Stability of Tailings Dams

Case Western Reserve University, Cleveland OH

Investigators

Abstract

This action is to provide partial support for an International Workshop on Seismic Stability of Tailings Dams, being jointly organized and sponsored by the National Science Foundation, the Office of Surface Mining (a bureau of the U.S. Department of the Interior), and the Mine Safety and Health Administration (an agency within the Department of Labor). Tailings dams are the residue of the milling process used to extract materials of interest from mined ores. They are characterized by hydraulically placed fills held in place by an embankment. Failure of tailings dams due to earthquakes has occurred many times in the past in several Pacific Rim earthquake-prone countries, causing significant loss of property and human lives, as well as severe environmental problems. According to the most current data supplied to the National Inventory of Dams, there are 860 coal-mining related dams in the United States. Of these, 232 are considered to have a high hazard-potential by FEMA's hazard rating system, indicating that failure would be reasonably likely to result in loss of life and significant property damage. The vast majority of these high-hazard-potential dams are coal refuse tailings dams located in the Appalachian Coal Field. A few are over 200 m (600 feet) high. Failure of such a structure due to earthquake loading would be catastrophic. Even though considerable progress has been made in seismic design and analysis of earth dams, little research has been conducted on the seismic stability of tailings dams. Past research has shown that coal waste materials have mechanical properties quite different from that of most soils. The structure and construction method of tailings dams are very different from conventional earth dams. Therefore, there is an urgent need for research to investigate the stability of tailings dams under earthquake loading, and to develop seismic design procedures suitable for this unique type of structure. This workshop will bring together US and international experts to discuss the critical issues involved. The objectives are: 1) to summarize the current state-of-the-art, and the state-of-the-practice in the design and seismic analyses of tailings dams; 2) to identify research needs; 3) to facilitate communication and collaboration between researchers, government regulatory agencies, and practicing engineers. Within the limits of the required expertise, the organizers will include underrepresented minorities. The workshop will be hosted by the Department of Civil Engineering, Case Western Reserve University in Cleveland, Ohio on 22-23 May 2003. The workshop proceedings will be posted online on the workshop web site and the web sites of the government regulatory agencies.