Geotechnical considerations of deep mine shaft, sinking by combined VSM and drill and blast construction methodology

Abstract

The vertical shaft sinking machine (VSM) is an innovative method of mechanized shaft excavation and liner construction technology developed in the context of rapid mechanical shaft sinking. This paper highlights geotechnical design considerations of VSM use for the upper section of a shaft prior to proceeding with conventional drill and blast methodology below the VSM section, in the perspective of deep mine shaft construction. Segmental liner stability and hydro-sealing concerns including liner basal stability, the detrimental effect of slurry on liner watertightness, liner deviation, and settlement are identified as important factors. Considerations of ground improvement prior to shaft sinking are also discussed. A good understanding of the geotechnical, geological, and hydrogeological characteristics of the ground are key to the optimization of the VSM liner depth.