Estimating Saturated Hydraulic Conductivity from Compression Curves for Fluid Fine Tailings

ABSTRACT: The hydraulic conductivity – void ratio function of oil sands fluid fine tailings (FFT) is a critical parameter to the performance of tailings management plans, and strongly influences how soon tailings deposits will be ready for reclamation. Unfortunately, determination of field applicable hydraulic conductivity functions for fluid fine tailings is challenging. This paper considers estimation of the hydraulic conductivity function from the more easily determined compressibility function. Many researchers have correlated the consolidation stress σ’, void ratio e and saturated hydraulic conductivity k with easily attainable index properties (e.g. consistency limits, density, grain size distribution curves various types of soil. Previous work showed that such methods do not predict the hydraulic conductivity at higher void ratios with sufficient accuracy. This paper examines and assesses the predictability of the hydraulic conductivity function from the compressibility function using regression models, and also examines how such regression models can be improved by the use of single measured value of hydraulic conductivity. Analyses of a large database of FFT and amended FFT shows that the strategy of including one measured value of hydraulic conductivity substantially improves the predictive power of such regression models. A hypothetical large strain consolidation prediction is included to help quantify the relatively accuracy of the regression models.