68th Canadian Geotechnical Conference and 7th Canadian Permafrost Conference

STABILITY DESIGN OF A TAILINGS DAM ON A GLACIOLACUSTRINE CLAY FOUNDATION

Session: Problematic Soils and Ground Improvement I / Sols problématiques et amélioration du comportement I

Jérôme Lapierre, AMEC Foster Wheeler (Canada)
Desheng Deng, Amec Foster Wheeler (Canada)
Gilles Bouclin, Amec Foster Wheeler (Canada)
Luciano Piciacchia, Amec Foster Wheeler (Canada)

As part of a tailings management mandate, new tailings must be stored in an inactive, existing tailings pond situated in Abitibi, Quebec. In order to confine the hydraulically deposited tailings, several dams will be built on soft, varved clays of glaciolacustrine origin. Field vane tests have revealed undrained shear strengths as low as 13 kPa. In order to ensure the timely delivery of the dams and to meet the design factors of safety at all times, the use of stability berms is proposed in conjunction with an observational design approach. As construction is done in stages, monitoring of pore pressures and consolidation will provide the field data required to update the numerical models and the design, if required.