Seismic induced liquefaction of cemented paste backfill: Effect of mixing water

Cemented paste backfilling (CPB) is a mixture of tailings, water and cement that is used as tailings disposal method to minimize geotechnical and environmental risks associated with mine waste management. Fresh CPB placed into a stope can fail due to liquefaction during earthquakes, causing injuries/fatalities and significant financial consequences for mines. CPB behavior could be affected by the chemistry of pore water which often contains sulphate ions. This study aims to assess the effect of the chemistry (sulphate content) of the pore water on the earthquake-induced liquefaction of fresh CPB. Shaking table tests (0.13 g of peak ground acceleration) are performed on fresh CPB materials with and without sulphate ions in the pore water. The obtained results show that the presence of sulphate in the mixing water increases the susceptibility of CPB to liquefaction. The findings in this research will contribute to more cost-effective design of CPB structures.