Fig. 13.
Three graphs, labelled a, b and c, plot specific volume e vertically against mean effective stress p prime in kilopascals horizontally. Graph a has a logarithmic horizontal axis from 1 to 1,000 kilopascals, with labelled values at 1, 10, 100 and 1,000, and a vertical axis from 1.45 to 2.10 in intervals of 0.05. The legend identifies C o T T R X 86 S, C o T T R X 91 S, C o T T R X 95 S, C o T S S and C o P T R X S S from the current study. It also identifies Deixing copper, Li, 2017; Copper S 1, Copper S 2 and Copper S 3, Vergaray et al., 2023; Copper T S F 2, Karim et al., 2022; Copper upper beach 86 N, 91 N and 95 N, Velten et al., 2024; Copper lower beach 86 N, 91 N and 95 N, Velten et al., 2024; Iron U B, Iron M B and Iron P O, Li, 2017; Iron F and Iron S, Consoli et al., 2024; Iron S 1 and Iron S 2, Wagner et al., 2023; Gold, Li, 2017; and Gold, Bedin et al., 2012. Copper upper beach 95 N is additionally distinguished by square markers. All datasets decrease in specific volume as mean effective stress increases, but their starting levels and curvature differ. The comparison curves occupy approximately 1.61 to 2.06 at lower stresses and approximately 1.49 to 1.75 towards 1,000 kilopascals. Gold, Li, 2017, begins highest at about 2.06 and decreases towards approximately 1.70. Gold, Bedin et al., 2012, begins near 1.93 and decreases towards approximately 1.69. The copper upper beach and lower beach curves generally begin between approximately 1.83 and 1.95 and decrease towards approximately 1.65 to 1.75. Several iron curves begin between approximately 1.73 and 1.92 and decline towards approximately 1.49 to 1.72. The current-study C o T T R X 86 S, 91 S and 95 S curves begin near approximately 1.72, 1.65 and 1.61, respectively, and decrease gradually towards approximately 1.55 to 1.58. The dotted C o T S S curve begins near 1.70 and curves more steeply downwards, reaching approximately 1.46 before 1,000 kilopascals. The C o P T R X S S line begins near 1.89 at about 10 kilopascals and descends approximately linearly to about 1.54 near 1,000 kilopascals. Graph b has the same logarithmic horizontal scale from 1 to 1,000 kilopascals and vertical range from 1.45 to 2.10. It retains C o T T R X 86 S, C o T T R X 91 S, C o T T R X 95 S, C o T S S and C o P T R X S S from the current study and compares them with Deixing copper, Li, 2017; Copper S 1, Copper S 2 and Copper S 3, Vergaray et al., 2023; Copper T S F 2, Karim et al., 2022; and Copper upper beach and lower beach 86 N, 91 N and 95 N, Velten et al., 2024. Copper upper beach 95 N again uses square markers. The iron and gold datasets included in graph a are absent. The comparison copper curves generally start between approximately 1.80 and 1.93 and curve downwards with increasing mean effective stress, reaching approximately 1.63 to 1.75 near the upper stress range. The five current-study curves retain their positions and decreasing forms from graph a. Graph c isolates C o T S S and C o P T R X S S from the current study and Copper T S F 2, Karim et al., 2022. The horizontal axis is logarithmic and extends from approximately 1 to 1,000 kilopascals, while the vertical axis ranges from 1.45 to 2.10 in intervals of 0.05. The dotted C o T S S curve begins at approximately 1.70, decreases gradually at first and then more steeply to approximately 1.46. C o P T R X S S forms a nearly straight descending line from approximately 1.88 near 10 kilopascals to approximately 1.55 near 1,000 kilopascals. Copper T S F 2 begins near 1.75 at low mean effective stress, decreases gradually and then more steeply, reaching approximately 1.50 towards the upper end of the plotted stress range.Critical state line (CSL) of various tailings samples for comparison: (a) all tailings samples; (b) only copper tailings; and (c) only CSLs obtained from SS or DSS tests