GROUND SUPPORT & ROCK REINFORCEMENT
consolidation down to 420 m, along with an auxiliary column of plastic rods located at 200 m depth to create a physical barrier for segmented injection.
To carry out segmented consolidation, a custom drilling layout was developed. Raisebore diameter was 3 m, with 8 drill holes distributed along the full 420 m depth. Drill holes were positioned 0.6 m from the projected shaft wall, spaced 1.6 to 1.8 m apart. This ensured optimal coverage without compromising ground stability. Drilling was performed in strict accordance with design parameters to ensure accurate hole placement and avoid creating unnecessary weak zones.
The challenge of controlled ground consolidation led to the use of an innovative segmented injection method. The strategy involved using a single drill hole for injections at two distinct depth intervals, allowing for targeted treatment of the affected zones.
The operation began with the installation of an SDA rod column down to 420 m. Then, a second SDA column was installed up to 200 m. To prevent mixing between the injection segments, a Big Bag system was deployed at the tip of the plastic rod column at the 210 m depth. This system effectively sealed the hole at 210 m, creating a physical barrier that prevented resin from the deeper
zone from rising into the upper zone. Once sealed, resin injection started in the deepest section. The resin was injected in stages, first filling the annular space between rods and hole walls, followed by resin migration through fractures within the 330-420 m range. A 60-minute setting time was employed to maintain injection zoning and prevent resin migration into adjacent layers.
After completing the deep zone injection, the second SDA column was used for injection up to 200 m. In this segment, a resin with a 30-minute setting time was used to promote rapid and controlled consolidation.
Injection was performed in a controlled manner in each segment, ensuring that highly altered zones received more resin, while stable zones were left untreated. This approach allowed for precise consolidation, limiting resin spread and preserving the structural integrity of the surrounding ground.
The segmented pre-consolidation implemented in the raisebore shaft successfully stabilised the ground, ensuring shaft wall integrity. The selected resin, with its high cohesive strength, bonded loose strata and formed a continuous support beam along the shaft wall.
Its low viscosity allowed it to migrate
through small fractures, rebuilding the rock matrix and reinforcing formations without causing blockages. The precise and controlled consolidation in the most critical sectors ensured the process was executed without compromising the structural stability of the raisebore.
Weber Mining:“ The innovative, segmented approach to raisebore preconsolidation not only addressed the geological challenges of the terrain but also ensured precise and efficient ground stabilisation. The use of advanced injection techniques, specialised resin, and segmented methodology contributed significantly to the success of the project, safeguarding the stability of the shaft and surrounding rock formations.”
Epiroc’ s pumpable resin journey
Epiroc’ s pursuit of innovation in underground rock reinforcement began in earnest in 2011 with the launch of the‘ High Performance Bolting’ project. At the heart of this project was a bold ambition: to double bolting speed compared to traditional longterm bolt types. The need was urgent as rock reinforcement had become a critical bottleneck in underground operations.
Through years of intensive research and development, close collaboration with industry partners, and rigorous
Bradken ® Undercarriage For PC7000 Excavators
Enhanced Replacement Product
Bradken ® has long been the designer and manufacturer of aftermarket crawler shoes for PC5500 and PC8000 ultra-class range of machines, with over 8,200 * shoes delivered in the past decade, equating to 88 machine fitments.
This knowledge and expertise in the Komatsu ® PC range of excavators has now been utilised to develop undercarriage solutions for the PC7000.
Our proven track record over four decades in design and manufacturing capabilities for these machines’ undercarriage components has been demonstrated through the delivery of improved wear results of our crawler shoes, with 35 % longer wear life for Bradken ® shoes # as measured in comparison to competitors’ shoe wear life.
SCAN TO LEARN MORE
* Bradken ® delivery results between 2016-2023.
#
Results of case study undertaken in oil sands conditions in Alberta Canada, on the PC8000 crawler shoes compared with competitor shoes in same conditions.
DELIVERING AN
OPTIMISED FUTURE