Geotechnical Systems - DYWIDAG Strand Anchors
DYWIDAG Strand Anchors are an actively tensioned ground anchor system and correspond to DIN 4125 and EN 1537 specifications. Tensioning minimizes or eliminates anticipated deformations of the system and deformations at the civil engineering measure. This applies both to temporary structures (e.g. pit support systems) and permanent tie backs. The strand anchors are produced with double corrosion protection (DCP): each individual strand is covered by corrosion protection compound and inserted into an individual duct in the factory. As long as the grout used for anchoring is load-bearing, the anchor force is unlimited because the number of strands that can be combined in the anchorage is variable at will.
By definition, an anchor consists of three main components:
- Bonded length: The anchor is fixed in the borehole using grout (cement mortar) and can transfer the forces to the loadbearing soil via bond and skin friction
- Unbonded length: Each strand is uncoupled from the borehole using individual ducts so that it can freely extend in the unbonded length. This way, tension can be applied to the anchor system
- Anchor head: The anchor head transfers the anchor force to the substructure and thus to the structure that needs to be anchored
Once the grout has sufficiently hardened, the load bearing capacity of each anchor is tested during an approval test.
- Large degree of flexibility: Force, length, transport, installation
- There are practically no restrictions in terms of length – 150m
- Small pack size for transportation
- Amount of required space is very small during installation
- Retensioning or detensioning thanks to exterior thread at the wedge plates
- Permanent strand anchor can be supplied in many variations (standard, El-Iso, TWIN-Corr)