Measurement and prediction of internal stresses in an underground opening during its filling with cemented fill

The recovery of underground hard rock ore bodies often involves the use of mine fills. The type of mine fill depends on the mining methods and sequences. Where later recovery is dependent on stability of exposures of earlier placed fill, cement and/or cementitious materials are added to the fill. Once such fill type is pastefill which is in fact becoming a standard practice in Canada (e.g. Landriault 1995, Landriault & Tenbergen 1995, Naylor et al. 1997). However, the use of pastefill to maintain ground stability involves some difficulties related to the complexities of its behaviour. These complexities are due to the continuous evolution of the properties of cemented fill during placement, consolidation, and hardening due to the hydration of binder agents.