Tensile strength and dilative characteristics of compacted unsaturated clay-sized metalliferous tailings for bulk earthworks

Lack of investigation into the tensile strength characteristics of unsaturated tailings hinders their recycling as construction materials in bulk earthworks. Here, the strength characteristics and strength-dilatancy relation in the tensile stress regime of unsaturated tailings were investigated via flattened Brazilian and direct shear tests. A nonlinear variation of tensile strength with water contents was observed. The unsaturated tailings with water contents below the plastic limit were strain softening and dilative under low normal stress. Furthermore, an analytical equation was proposed to predict the tensile strength of compacted tailings via the soil water characteristics curve (SWCC) and corroborated via experiments.