In the heart of the Sibanye-Stillwater Bambanani mine, nestled within the Turffontein Shear Zone, a formidable challenge awaited the team from Provest. Led by Werner Janse van Rensburg, Regional Manager for Western Limb Operations, Provest embarked on a mission to ensure the safety and stability of mining operations in this geologically complex environment. Despite the challenges we encountered, our team successfully completed the project within the specified timeline.

The Turffontein Shear Zone, with its unique geological and geotechnical features, presented a complex puzzle. The team from Provest took on the task with enthusiasm, driven by a commitment to excellence and safety. The client drilled exploration boreholes, a strategic move to understand the rock mass’s characteristics. The drill core analysis revealed two distinct geotechnical zones: the damage zone and the fault core.

To combat these challenges, we collaborated with the client to devise a robust support strategy. Systematic 3.5-metre-long tension cable anchors were installed as primary support. To further reinforce the rock mass, they used Oslo straps, reduced bolt spacing to one meter along strike, and applied a 50mm thick layer of shotcrete.

Collaboration with the client, Sibanye-Stillwater, was crucial. The client introduced shorter rounds to ensure the stability of hanging wall and sidewall conditions post-blasting. This adaptation required Provest to be flexible and innovative, ensuring that their support strategies meshed seamlessly with the client’s safety protocols.

Safety was the compass guiding Provest’s every move. Adhering strictly to the Trigger Action Response Plan (TARP) procedure, the team conducted barring following a meticulous 13-step process. The installation of cable anchors was executed in a controlled, sequential manner, progressing from the back of the panel towards the front. This methodical approach ensured that each step taken was a step towards a safer mining environment.

Provest’s support strategies were not just about meeting standards but setting new benchmarks. Extensive barring was conducted in the panels, following the 13-step safe barring procedure. The sequential installation of cable anchors from the back towards the front, and from the up-dip side towards the downside, provided additional stability. Mechanical props were strategically installed at specific intervals, adding another layer of protection.

Monitoring was a cornerstone of Provest’s strategy. They kept a close eye on the stand-up time of unsupported spans in various geological conditions. This data was vital in informing decisions about the installation of tension cable anchors and the application of shotcrete. Ground movement monitors were employed to detect any signs of movement, enabling the team to respond swiftly to ensure crew safety.

Provest had to contend with pegmatoidal intrusions that disrupted the reef structure, intersecting self-mining, as well as highly serpentinised friable ground conditions that led to temporary halts in mining activities. However, through meticulous planning, strict adherence to safety protocols, and innovative support strategies, Provest overcame these obstacles.

Recognising the arduous conditions and the team’s relentless efforts, Provest’s team participated in a bonus scheme. All crews earned an additional 30% bonus, driven by shorter rounds blasted by the client and the adverse ground conditions in the shear zone. This incentive not only boosted morale but also underscored Provest’s commitment to safety and performance.

The outcomes of this project have significantly enhanced Provest’s understanding of shear zones and related geological phenomena. Our support strategies have set a new benchmark for safety and stability in mining operations within complex geological settings.

Provest’s journey through the Turffontein Shear Zone is a testament to our expertise in rock engineering and geotechnical support. Our meticulous planning, innovative approach, and steadfast commitment to safety have not only ensured the stability of the Bambanani mine but also set a new standard in the industry. This project stands as a shining example of Provest’s dedication to excellence and our ability to navigate and conquer the most challenging geological landscapes.