Characterization of Unsaturated Tailings & its Effects on Liquefaction
Author: Bryan F. Ulrich, Jeffrey G. Coffin
Conference: Tailings and Mine Waste
Date: November 5-8, 2017
ABSTRACT
In the mining industry, it is becoming relatively common for filtered mine tailings to be stacked to a significant height (>100m) with little to no compaction. The resulting deposit can be loose and potentially unsaturated. Characterization of these filtered tailings facilities for slope stability and deformation under earthquake loading conditions can be complex due to the potentially unsaturated state. This paper presents a summary of test results from the assessment of a filtered tailings facility which is located in Latin America. Cone penetration tests (CPTs) and seismic velocity measurements (SCPTu) were carried out along with selected drilling, sam-pling and laboratory testing. The results of laboratory testing utilizing bender element testing indicate that the CPT-based liquefaction analysis could not be relied upon due to suction-hardening of the unsaturated tailings, and that the seismic wave tests were the more applicable approach to assessing the potential for liquefaction in this case. The paper presents the results of the characterization and the interpretation of the test data.
Download the full technical paper.