Seismic Liquefaction of Mine Tailings

The residual waste from mining processes, or tailings, are most commonly disposed of by mixing the ground rock with water and pumping them as a slurry into large lagoons retained by dams constructed from the coarser part of the tailings. The very loose state of the sediments in the lagoon promotes their liquefaction, so that the consequences of dam failure can be very severe, through loss of life, homes, livelihoods and widespread environmental damage from the release often of millions of cubic metres of waste. Since 1917 there have been more than 245 tailings dam incidents. The failure in 2008 in Xiangfen County, China, caused 277 deaths, but these disasters are by no means restricted to developing economies, and in 1985 at Stava, Italy, the debris flow resulting from the failure of a dam built on a hillside travelled down the valley at 90km/h killing 268. The project will investigate the liquefaction of tailings materials under seismic loading, collaborating with the China University of Mining and Technology, Beijing and Golder associates. The research will be of an experimental nature, by means of advanced laboratory testing in the Geotechnical Engineering Research Laboratory.