Chaitan Sandu
Principal – Dams and Geotechnics, Tetra Tech Canada

Selection of the Best Tailings Management Alternative for Dams Founded on Soft Ground at a Pre-Feasibility Level

In a pre-feasibility level study (PFS) for a future raise of an existing tailings dam at True North Mine near Bissett, Manitoba, consideration of the undrained behavior under future loading conditions is a key geotechnical factor in the basis of design of the dam raise. Three different construction methods were evaluated for raising the dam. Geotechnical evaluations included stability analyses using undrained shear strengths of the soft foundation clay layer and fine tailings. Piezometric water levels from existing piezometers and cone penetration test (CPT) dissipation results were compared with the as-built design pre-construction water level data to estimate the change in pore pressure conditions within the dam and to model the phreatic surface for stability analyses. State parameter and undrained shear strength values were calculated from the CPT data and material zones in the dam were verified from the borehole data.

 

Chaitan is Manitoba based Civil-Geotechnical Engineer, currently serving as Principal – Dams and Geotechnics at Tetra Tech Canada. He has 15 plus years of progressive and multifaceted experience in large scale engineering firms in Canada focused on business/strategy development for new market segments, planning, analysis, design & construction for Energy, Mining, Industrial, Water Resources & Public Infrastructure sectors across Canada, USA, Brazil, Mexico, and India. He also serves as the Vice Chair for CDA’s Mining Dams Committee and represents Canada on the joint Canadian and US initiative for developing risk informed decision making guidance for Tailings Dams for North America.