A comparison of procedures for determining the state parameter of silt-like tailings

Author(s): 
Mauro Sottile, Alejandro Kerguelen & Alejo Sfriso
Date: 
Tuesday, October 8, 2019
First presented: 
The 17th African Regional Conference on Soil Mechanics and Geotechnical Engineering
Type: 
Published paper
Category: 
Geotechnical

After recent failures related to tailings storage facilities, the assessment of static liquefaction has become a major subject of interest in the mining industry. The standard procedures to evaluate global stability under liquefied conditions combines limit equilibrium with trigger analyses, which have fallen short -in some cases- in putting geotechnical risk off the table. Thus, deformation modelling incorporating high-end numerical procedures is often called in, requiring the calibration of a large number of material parameters that entails uncertainty and condition the robustness of the approach. One of the most challenging parameters to calibrate in tailings deposits is the state parameter for silt-like tailings that fall in the intermediate region between clays and sands. This work describes the application of the Shuttle & Jefferies (2016) methodology to estimate the state parameter along CPTu soundings using numerical cavity expansion element tests using Norsand, and a comparison with a more conventional approach like the one by Been & Jefferies (2016). The spatial distribution of the state parameter, when determined using this procedure and fed into a dam section, allows for defining regions of similar expected behaviour within the tailings body. An application for a tailings storage facility is illustrated, the results of two screening methods are compared and discussed. 

Feature Author

Mauro Sottile

Mauro is a Civil Engineer from the Northeast National University (Argentina) and MSc. from the Massachusetts Institute of Technology (MIT). He has focused on the development of constitutive soil models and their implementation in commercial software such as Abaqus and Plaxis. He has knowledge on the implementation, calibration and use of constitutive soil models for the application of numerical methods in geotechnical design. Mauro also has experience in geotechnical laboratory and in-situ tests and recently participated in projects located in Argentina, Armenia, Australia, Bolivia and South Africa. Within his regular activities he collaborates as a teacher at the University of Buenos Aires, Argentina.

Senior Consultant
MSc in Geotechnical Engineering
SRK Buenos Aires
Alejandro Kerguelen

Alejandro Kerguelen is a Senior Consultant with over 10 years of experience in the design and supervision of geotechnical works. He has been involved in surface and underground operations in tropical and high mountain environments in different projects located in Argentina, Brazil, Chile, Colombia, Cuba, Guatemala, Paraguay and Uruguay. He has focused on probabilistic techniques for slope stability and rock-fall analysis. He has experience in software development using automation techniques and numerical simulation. Alejandro has developed teaching activities in the courses of Soil Mechanics, Solid Mechanics and Strength of Materials, including laboratory training and  research projects in the Faculty of Civil and Environmental Engineering at the University of Los Andes (Colombia).   

Senior Consultant
MSc in Geotechnical Engineering
SRK Buenos Aires
Alejo Oscar Sfriso

Alejo O. Sfriso is a Principal Engineer with 25 years of experience in geotechnical engineering for infrastructure and mining works. He is an expert in the application of numerical methods for geotechnical design and analysis. In addition to his activity at SRK, he is the Director of AOSA - Geotechnical Laboratory, Professor of Soil Mechanics and Geology of the University of Buenos Aires, Vice President for South America of the International Society of Soil Mechanics and Geotechnical Engineering for the period 2017 - 2021, former Professor of Geotechnics at the National University of La Plata and former President of the Argentinean Society of Geotechnical Engineering.

Principal Consultant
PhD, Civil Engineer
SRK Buenos Aires
SRK North America