SURELOCK® spin anchors are flexible high tensile steel strands of specific lengths, resin anchored inside a drilled hole with an innovative locking-off unit called the ‘SURELOCK® swivel barrel’ at the collar.
- The advantages of utilising this locking-off device is that once the required pre-stressed load is achieved, the shear ring shears on the barrel into a positive visual indicator with an audible knock.
- SURELOCK® spin anchors are made to requirements as specified by the end user. These anchors are designed to give immediate support and are normally post-grouted after being pre-stressed.
- These anchors are easily installed using trained support installation crews
- The cable anchors are manufactured to the required specifications of the customer e.g. the cut length of the strand, specified load at which the shear ring activates, number of bulbs
- All spin anchors are tensioned to the required loads as specified by the customer, with hydraulic equipment approved by the supplier
- The spin anchors can be installed in incompetent rock
- All spin anchors may be grouted either before or after pre-stressing the anchors.
Installation procedure for SURELOCK® spin anchors
Check the equipment and the anchor to be installed
- Check the 25 ton tensioner as per the daily maintenance list
- Chick the hydraulic pump as per the daily maintenance list
- Check the strand cropper as per the daily maintenance list
- Check the type of anchor – the length and that the other material is available, i.e. the bearing plate with the SURELOCK® barrel and wedge.
- Check the resin (fresh – within expiry date) and spinning tool.
Flexible anchor installation procedure
Before installing the SURELOCK® Spin Anchor, check the following:
- The length of the anchors, always add 0.5m for the tensioner
- The type of anchor, i.e. the spin anchor
- Invert the anchor and push it to the back of the drilled hole, if 0.5m of strand is left protruding from the hole, then the depth of the drill hole is correct
- Check the diameter of the hole. If it is not to the correct specifications, i.e. oversized or undersized, the anchor could slip inside the hole, or not be able to enter the hole
- Insert the resin capsules with caps into the collar of the drilled hole and gently push the capsules to the back of the hole
- Push the spin anchor with the two bulbs into the hole and give a quick jab so as to break the resin caps
- Connect the spin anchor strand to the spinning tool and commence to operate the spinning tool, slowly pushing the spin anchor through the resin for approximately 45 seconds until the resin and its catalyst have mixed with one another
- Hold the spin anchor cable until the resin inside the drilled hole has set and remove the spinning tool from the protruding strand
- Clean the protruding strand with a clean cloth
- Place the anchor bearing plate over the strand through the centre hole until it is flush against the collar of the hole
- Push the SURELOCK® barrel and the wedge over the length of the protruding strand, until flush against the bearing plate.
- Connect the hydraulic tensioner to the hydraulic pump
- Push the tensioner with the jack nose over the protruding strand until flush up against the SURELOCK® barrel
- Operate the hydraulic pump until the shear ring of the SURELOCK® barrel collapses
- Never let anyone stand directly behind the tensioner whilst in operation
- The anchor is now pre-stressed to the specified load
- Reverse the control of the hydraulic pump and operate until the tensioner is loose on the protruding strand
- Remove the tensioner and connect the strand cropper to the hydraulic pump and cut the protruding strand approximately 100mm from the SURELOCK® barrel
- The anchor installation is now complete. Proceed to the next hole.