A geomechanical study for a shaft wall rehabilitation program

In October 1995, a relatively intense period of microseismic activity occurred close to the Golden Giant Mine 4600 m level shaft station. This activity resulted in visible deterioration of the shaft station area, parts of the 4600 m level footwall access drift, and the shaft walls above the 4600 m level. A site investigation, that included a geomechanical shaft wall mapping program and numerical modelling study, was used to develop a rehabilitation and monitoring strategy for this area. The methodology used to develop the rehabilitation strategy incorporated several useful geomechanical approaches that can be applied to any investigation of rock deterioration. These approaches include underground observations, shaft wall geotechnical mapping, borehole camera surveys, core logging, numerical modelling, microseismic monitoring and deformation monitoring.