Piezocone penetration testing of fallow and operational tailings storage facilities

Piezocone Penetration Tests (PCPTs) were conducted on both operational and fallow Tailings Storage Facilities (TSFs), five years apart in the Western Australian goldfields. Changes over the five year period were observed after comparison of the shear strength and pore pressure profiles. Notably, significant increases in strength were observed near the surface of the fallow TSF due to evaporative desiccation occurring. The PCPTs conducted on the operational TSF identified that the majority of tailings had gained strength and consolidated but that zones of weaker, unconsolidated material persisted. It was also observed within the operational TSF the pore pressure profiles correspond well with existing piezometer data and observed seepage stains.