Geotechnical design verification and performance assessment of tailings storage facilities

Abstract

Tailings storage facilities can represent one of the greatest risk sources for a mine site, and the geotechnical design of any such facility should be conducted at a level appropriate for the satisfactory management of that risk. During operation, work is required to verify the geotechnical design parameters and conditions, which, at least for the deposited tailings, must often be assumed in the design stage, and to assess the performance of the facility, including consideration of eventual closure and reclamation. Topographic surveys, piezocone soundings, piezometer readings and seepage monitoring are among the most commonly used methods to characterise storage capacity, strength, rate of consolidation, porewater pressure and seepage conditions within tailings deposits. Some aspects of the collection, presentation and use of data from these monitoring and in situ testing methodologies for verifying geotechnical design assumptions are discussed in this document, with particular reference to tailings facilities for which structural support is provided by the impounded tailings. Advances in equipment, field work and data acquisition have improved the quality and quantity of geotechnical information and should lead to further development of tailings-specific geotechnical databases and correlations at each mine site and across the industry as a whole.