RIX has years of experience in underground overhead shotcrete application for ground support in mines and tunnels. Our in-house trained hand and robotic nozzlemen, operators and management ensure that all aspects of overhead shotcrete application contracts are completed safely, professionally and with high quality.
RIX shotcrete/fibrecrete services in mining and tunneling:
- In-cycle robotic shotcrete/fibrecrete application
- Tele-remote shaft lining
- Hand spraying in limited access areas – wet and dry spray
- High walls, box cuts, mine and tunnel drives and portals
- Cross-passages, both overhead and architecturally finished at openings to match pre-cast elements in TBM driven tunnels
- Mix design and optimisation
- Advice and assistance in shotcrete plans, equipment, project set-up and programing
Shotcrete for ground support in Australian underground mines has seen massive growth over the past 30 years. During that time, the introduction of mechanised spraying, fibre reinforced shotcrete and in-cycle shotcreting improved safety and mining processes dramatically by reducing the need for personnel to enter unsupported ground.
The introduction of the in-cycle shotcrete/fibrecrete process meant that fibrecrete could be applied during the development cycle – after blasting but before bolting. The introduction of fibre meant that mesh reinforcement no longer needed to be installed, robotic spray arms or booms allow the shotcrete rig operator to stand under the supported tunnel roof, and the bolts were then drilled through the fibre-reinforced shotcrete layer with the bolt plates over the fibrecrete spreading the load and providing optimum connection to the substrate.
Shotcrete can be used in tunnels as either a temporary or final lining. Temporary shotcrete or fibrecrete linings progress with the tunnel development, followed by a final lining of either shotcrete, cast in-situ concrete or pre-cast segments. With the improvement of waterproofing systems, Single-Pass Tunnel Linings (SPTL) that comprise of fibre-reinforced shotcrete (or fibrecrete) and a combination of rock bolts, cable bolts and steel arches (where extra support is required) has become a significant method of ground support for civil tunnel construction.
Centre: Shotcrete application equipment spraying the roof of the Cross City Tunnel located in Sydney. Tunnel ribs and steel reinforcement can be seen within the shotcrete structure.
Left: RIX specialist application personnel hand-spraying a mine portal entrance.
Right: A Jaycon MaxiJet Boom on a Jaycon MidJet Rig. Unsupported ground demands safety and RIX specialist shotcrete application equipment can be controlled remotely by the operator safely positioned in the supported area. The pump itself incorporates a long-stroking, large volume, piston shotcrete pump. Chemical dosing of accelerators for overhead applications can be programmed and electronically metered for application and quality assurance.