Entezari, I, McGowan, D, Glavina, J & Sharp, J 2023, 'A comparison between in situ techniques to measure undrained shear strength of oil sands tailings', in GW Wilson, NA Beier, DC Sego, AB Fourie & D Reid (eds), Paste 2023: Proceedings of the 25th International Conference on Paste, Thickened and Filtered Tailings
, University of Alberta, Edmonton, and Australian Centre for Geomechanics, Perth, pp. 787-797, https://doi.org/10.36487/ACG_repo/2355_62
A comprehensive comparison between undrained shear strength (Su) measured from piezocone penetration tests (CPTu), piezoball penetration tests (BCPTu), and electronic field vane shear tests (eVST) in soft tailings is presented. To evaluate the comparability of Su from both penetrometers and eVST, a comparative study was performed using data collected from oil sands tailings storage facilities in northern Alberta, Canada. Two paired datasets of eVST-CPTu and eVST-BCPTu were compiled and the relationships between Su values from the three strength measurement techniques were explored. Results show that Nkt and Nball of 15 and 12.2 are reasonable values to scale net tip resistance and determine the strength in soft tailings from CPTu and BCPTu, respectively. Furthermore, comparing to eVST results, both CPTu and BCPTu penetrometers were found to be effective tools in profiling the strength of soft tailings when Su is less than 10 kPa. BCPTu was observed to be slightly more accurate than CPTu in very low strength fluid-like tailings.
Keywords: undrained shear strength, field vane shear test, piezocone penetration test, ball penetration test, soft tailings
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