AbstractsEngineering

Millions of tons of coal refuse are produced every year and need to be stored in the coal waste tailings dams. Since the impounded fine coal refuse has high water content and low shear strength, the tailings dams is susceptible to the flow failure under static and dynamic impact loading. In some other cases, the coal slurry might break through into the adjacent or underground mines and thereafter flow into the groundwater resources and river ecosystems. It has been known that flow failure of coal waste tailings dams would cause severe property damage, loss of human lives, and environmental issues. Without adequate information and measurement techniques, there is no comprehensive study reported on the properties and flow behavior of impounded coal refuse as well as the failure mechanism. In this study, a comprehensive investigation was carried out on the geotechnical properties and flow behavior of impounded coal refuse under static and impact loading by using a range of laboratory tests, small-scale model tests, and centrifuge model tests. The combined results would help to better understand the flowability of coal refuse and the failure potential of tailings dams. In addition, a potential countermeasure was proposed by using slurry cells. Its effectiveness in reducing the risk of flow failure was evaluated in centrifuge model tests.