Results of a backfill monitoring programme at Vaal Reefs 5 Shaft

Abstract

This report documents the results of the in situ measurements carried out in the 68-52 stope at Vaal Reefs 5 Shaft. The in situ stress-strain behaviour of classified tailing backfill has been measured in panel P3. There is good agreement between in situ measurements and laboratory determined confined compression results for backfill with a porosity of 43 percent. The complete backfill rib behaviour which has been determined for this location is similar to the behaviour observed at other mines. An excessive amount (four to seven percent) of shrinkage is indicated by the results and this has led to low backfill stress levels and a reduction in face area support benefit.