Characterizing a filtered stabilized metallurgical residue with PMT

This paper illustrates how pressuremeter testing may add value to geotechnical characterization of tailing storage facilities (TSF). This is done with reference to results obtained in a campaign on jarosa, a lime-stabilized filtered jarosite residue that results from electrolytic zinc production. These residues are often stabilized chemically to minimize environmental con- cerns. The resulting stabilized product is disposed of by stacking in large deposits. Geomechanical characterization of the resulting stabilized residue, which is necessary for safe evaluation of the deposit mechanical stability, is more complex than that of other TSF, because of the presence of bonding and partial saturation. Pre-bored PMT results help to understand better the results from CPTu classification, offer good estimates of the at rest coefficient of earth pressure K0 and allow to calibrate CPTu for "in situ" identification of yield stress, a key design parameter in TSF storing filtered and/or bonded materials.