GFRP Cuttable Anchors
DYWIDAG Anchor Systems
When temporary anchors are installed into ground that has potential for future development, an alternative solution to the removable anchor system is the cuttable anchor. Glass Fiber Reinforced Polymer bar has been used for passive systems such as rock bolts and soil nails for some time; however, as a material which is easily cut, it can provide specific qualities desirable temporary pre-stressed systems too.
GFRP can take large tensile forces and so lends itself to ground anchoring however due to the materials reduced shear strength compared to steel, the full strength of the bar can not be utilised as the thread form is the limiting element in the system. To compensate for this, several bars form the anchor and combined at the head plate to form a cluster of bars within the anchor.
GFRP anchors are most efficient if they are installed in a single section as the use of couplers will further reduce the load capacity of the bar. GFRP Anchors are light weight and easily lifted into position.
Following their use, these anchors can be de-stressed and left in place. The anchor head can be removed and the bars cut off at the head. If the anchor tendons are encountered below ground at a later date they will be easily cut by an excavator or Tunnel Boring Machine without causing and damage to infrastructure above ground or causing delay to the progression of the tunnel.