This picture was taken at a mine in the DRC after one of the open stopes had collapsed due the the intersection a very weak hangingwall contact as well as several fault structures. The mining and technical teams were contemplating the effect this fall had on production as well as what remedial actions can be implemented to reduce this from happening again on other levels where similar conditions have been noted.
Sunset in the Kalahari. The photo was taken at Assmang Khumani Mine in the Northern Cape. It was snapped next to the mine's Real Time Monitoring Radar :) . The view here is amazing, especially in the early hours and just before sunset.
Watching the charged-up pillar for the final blast of the pillar project at Dwarsrivier Chrome Mine. The two adjacent pillars have already been extracted at this stage with the blast barricades, or what is left of them, to protect the very sensitive instrumentation from blast damage.
Koidu Limited Diamond Mine
This photo was taken at Jindal kiepersol colliery in March 2022, a few moments before going to experience pillar extraction for the very first time.
K1 Level 6 Development, Koidu Mine Sierra Leone, routine support audit.
This photograph was taken at around 150 metres below surface at Bayer Chrome Mine in early 2007 whilst evaluating an option of reopening and extending an old on reef decline system. It shows footwall that has buckled up into a roadway between two of the decline system protection pillars reducing the open height of the roadway by approximately 1 metre. It appears most likely that the presence of a sheared parting plane and jointing in the footwall provided release surfaces allowing the upward movement of the footwall. This was triggered by additional loading of the decline protection pillars as a result of extensive panel pillar failure in the areas on either side of the decline system. An isolated 50 metre high ridge of hills located over these workings seems to have been the prime contributing factor initiating the pillar failure process.
New adits being created from a highwall.
Wedge failure behind the last of supports, which was to standard. The recommended angle to pin the wedge was not adhered to due to the jumper stacking in hangingwall. The second hole was drilled and the installed Instope missed the wedge and the FOG came out with the blast.
Photo taken at South deep gold mine, low profile destress section, depicting stress fracturing around the tunnel "into the pillar" and its contribution to pillar scalling.
I took this picture in 2016. To me this picture represents rock engineering at its most basic - Keep the hanging wall hanging! What happened here was that mining, for once, properly followed a reef roll. Some time later the entire bowl detached and came to rest on the support.
Initial develop 4m wide and 3.5m high destress excavation with crush pillars on both sidewalls. Then place backfill bag on one side of the sidewall. It is then develop Long Hole Stope to be 14m high sometimes. On the photo LHD is remotely cleaning the stope but FOG occurred.
While investigating rockburst damage at Mponeng on 2 October 2007, I photographed fractures and shear zones. I recently built a 3D model from some of those photographs and took snapshots from the model, the top snapshot looks obliquely down the panel, showing E1 and E2 fractures as well as the hangingwall above the backfill. The bottom snapshot looks back towards the backfill, focussing on the stress fractures in the hangingwall between timber props.
View of the open pit, through the open stope, from the underground tunnel. The open stopes were designed to hole into the open pit. The stope brow is visible with the clear sky in the background.
Photograph taken at South deep mine, showing Arch sets failure as a result of massive FOG.
The photo was taken in the longwall face after a face break had occurred. The stress induced cracks can be seen occurring between the coal face and chock canopies, and extending deep into the thick sandstone roof. These cracks formed mainly due to insufficient support offered by the chocks, causing the overlying layer to cantilever. Some of the cracks have intersected each other approximately 2 m into the roof forming large sandstone wedges. The area was repeatedly inspected by the onsite Rock Engineer mapping and monitoring these cracks. Mine: New Denmark Colliery. Photo taken: 19 April 2021
The photo was taken at South Deep following a seismic event that caused damaged to the excavations walls. The Mining method "HPS" high profile stoping / destressing method where mining was mainly done in a east to west direction. These mining ends traversed problematic bedding planes such as the MIT, MIQ and MBB. The photo taken provides a clear indication what impact geological weakness have on fracture patterns and surrounding rock masses.
Fall of ground occurred on a long hole stope brow whilst drilling was in progress and rocks fell on top of a Simba. Fortunately no one got injured. The FOG was a result of stress relaxation leading to tensile fracturing in the hangingwall. A prominent geological structure was traversing along the LHS brow and formed a wedge that later dislodged.
The simplicity of a geotechnical visual inspection.
Meya Mine in Sierra Leone. Meya River Decline Portal.
It is a photograph of The tunnel is 8.0m high.