Hydraulic anisotropy ratio of undisturbed tailings samples

This study determined the magnitude of the hydraulic anisotropy ratio (rk = kh/kv) in undisturbed tailings samples with varying fines contents. Constant-head permeability tests were performed under different consolidation stress levels and hydraulic gradients, evaluating the influence of effective stress, void ratio, and fines content on the compression index (Cc), the coefficient of consolidation (Cv), and permeability (k). To obtain rk, the experimental method of cutting samples in different directions was implemented. This method has been applied to obtain rk in various materials such as clays and rocks, but it is not known to have been used for tailings. The literature reports few rk values for tailings. According to different researchers, rk in tailings can vary from 2 for fairly uniform dams to 100 in transition zones, due to the intercalation of fine and coarse particles. In this study, rk values ranging from 1 to 10 were obtained, identifying fines content as the main factor controlling hydraulic anisotropy. Furthermore, three correlations were defined between fines content and initial and final void ratios.