DYWIDAG-SYSTEMS INTERNATIONAL
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Stay cable bridge between Rosario and Victoria, Argentina, DSI Services Supply and installation of 740 t DYWIDAG stay cables with DYNA Grip anchorages.

Stay Cable Systems

DYNA Grip® Anchorage

Project specifications often require that individual strands of stay cables to be inspectable and, if necessary, replaceable. For these requirements DSI developed the DYNA Grip® Anchorage providing the opportunity to inspect individual strands without damaging the stay cable and to replace strands if necessary.

The DYNA Grip® Anchorage consists of an anchor block in which the strands are anchored by 3 part-wedges with high dynamic performance. A ring nut is threaded on the anchor block to transmit the cable force via the bearing plate into the structure. A steel pipe, which incorporates centering and sealing provisions for the strands, is welded to the anchor block.

Fatigue tests have proven a dynamic stress range of up to 200 N/mm2 (upper stress 0,45 GUTS at 2 million load cycles). Tests with 0.6° inclined anchorages according to the new fib bulletin 30 were also successfully performed.

DSI DYNA® Grip Anchorage with elastomeric bearing to reduce the bending stresses in the strands caused by rotation.

Similar to the DYNA Bond® Anchorage, an elastomeric bearing is installed at a certain distance away from the anchor block to reduce the bending stresses in the strands caused by rotation.

Special features of the DYNA Grip® Anchorages:

  • the factory applied corrosion protection of the PE-coated strands continues directly up to the wedges. This significantly reduces the space in the anchorage which is ti be filled with corrosion protection compound and improves durability.
  • exact cutting to length of the strands and removal of the PE coating is not necessary. Using special equipment, the PE-coating is removed using a DSI developed, patented procedure during teh first stressing. In cases where subsequent stressing actions are necessary, the remainging PE-coating is compressed by the compression tubes held by the wedges while the strand is pulled through and elongated by the jack.
  • restressing and replacement of individual strands as well as of the complete cable is possible.


Similar to the DYNA Bond® Anchorage, an elastomeric bearing is installed at certain distance away from the anchor block to reduce the bending stresses in the strand caused by cable rotation.
A clamp, installed after stressing on the strand bundle, keeps the strand in a compact hexagonal pattern and acts as a support for the elastomeric bearing. In the drawing above, a version is shown that is able to accommodate construction tolerances between the cable axis and the axis of the recess pipe.

 

DSI DYNA® Grip Anchorage
DSI DYNA® Grip Anchorage Schematic Drawing
  1. Wedges
  2. Ring Nut
  3. Compression Tubes
  4. Sealing Plates
  5. Spacer
  6. Compression Plate
  7. Elastomeric Bearing
  8. Clamp
  9. Cap
  10. Anchor Block
  11. Bearing Plate
  12. Strands
  13. Recess Pipe
  14. Exit Pipe
  15. Filler Material
  16. HDPE Sheathing

 

 

 DYNA Grip®  Anchorage (forces calculated with strands 0,62" St 1670/1860)
cable typeDG-P12DG-P19DG-P31DG-P37DG-P55DG-P61DG-P73DG-P91DB-P109*
No. of strands1219313755617391109
Forces [kN] 
ultimate load (GUTS)3,3485,3018,64910,32315,34517,01920,36725,38930,411
Working load (0.45 x GUTS)1,5072,3853,8924,6456,9057,6599,16511,42513,685
Dimensions [mm] 
A - bearing plate300370460500600640715780855
B - thread**200220230240270275290310340
C - bearing plate5060758095100110120130
D - ring nut90110120130160165180200230
ØR - ring nut244287350378440480536600636
ØT - recess pipe219245299324368406457495521
ØP - HDPE Sheathing110140160180200225250280315

*up to 156 on special request.
**standard length, to be changed on special request.

The values are based on the German Code (DIN). Adaptations to other code systems or concrete strengths (e.g. ASTM, BS, etc.) are possible.

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