Seismic table investigation of the effect of inclusions on the cyclic behaviour of tailings

When subjected to cyclic loadings, such as those induced by earthquakes, hard rock mine tailings may undergo liquefaction. Such a response can be damaging to the tailings impoundment and, in the case of a breach, to the surroundings. Means must thus be considered to control or alleviate the risks due to liquefaction. This paper presents the main results of a laboratory investigation that focussed on the dynamic behaviour of tailings due to cyclic loading on a seismic table. Different conditions were investigated to assess the influence of various factors, including tailings density and the presence of rigid and (or) drainage inclusions. The main results obtained during the tests conducted on the tailings, with and without inclusions, are presented and discussed with an emphasis on the development of excess porewater pressures. The main limitations of this experimental work are also discussed. These results show that inclusions can have a significant effect on the dynamic response of the tailings and on the occurrence of liquefaction.