Friction rock anchors are simply a long length of open seam, high strength steel tube. One end is equipped with a welded steel ring which retains a bearing plate. The opposite end is tapered to facilitate easy insertion into the drilled hole in the rock. The friction rock anchor is driven into a drilled hole slightly longer and slightly smaller in diameter than the unit. The slot along the length of the tube is compressed as it is driven into the drill hole. The outward radial force generated by the compressed tube on the surrounding rock, anchors it in the hole.
- As a temporary, quick and easy support in development ends prior to the installation of more permanent support (should this be needed)
- Securing of wire mesh in underground excavations, road cuttings and open pit highwalls
- As an anchor to hang pipes and cables.
Hole sizes should be 1 to 4mm smaller in diameter than the FRA to be installed, this is important for good performance.
|Recommended hole diameter (mm)||30 – 32||35-38||38-41||41 – 45|
All four diameters are available in standard lengths from 0.6m to 3.0m in increments of 0.3m
Non-standard lengths are available on application.
DOMED BEARING PLATES (WITH OPTIONAL DOG EAR)
|Length mm||Width mm||Thickness mm||Hole size mm*|
|125||125||5 or 6||34, 40,43 or 47|
|150||150||5 or 6||34, 40,43 or 47|
* Determined by FRA diameter
- These units are easy to install and all that is required is the appropriate driving tool and a percussion type drill (jackhammer, jackdrill, stopper etc).
- Drill a hole 1 to 4mm smaller in diameter than the FRA to be installed
- Place the driving tool into the chuck of the drill
- Place the bearing plate over the tapered end of the FRA
- Place the tapered end of the FRA into the collar of the drill hole and align
- Start the drill and drive the FRA home until the bearing plate is hard up against the rock face.
Tools are available for all three sizes of FRA.