Removable Anchors - Technical Data
Removable Strand Anchors are constructed from 15.7mm Standard Strand (Grade 1570/1770 N/mm2), with a heat treated rupture point.
| Number of Strands | Ultimate Strength | 0.1% Proof (Yield Strength) |
| | kN (fpu) | kN (Ty) |
| 1 | 220 | 137 |
| 2 | 440 | 275 |
| 3 | 660 | 412 |
| 4 | 880 | 550 |
| 5 | 1100 | 687 |
| 6 | 1320 | 825 |
Higher capacity anchors are available through the addition of further strands.
Notes:
- Ultimate Strengths are based on the failure load at the rupture point.
- Working Loads incorporate Sf of 1.6, in accordance with temporary anchors (BS8081).
- Yield Strengths Ty of free length tendons exceed failure load at rupture point.
Permanent Conventional Bond Lengths
(Firm Ground) | | Staged Bond Lengths
(Poor Ground) |
 | | 1 | - | Three Part Wedge | | 2 | - | Bearing Plate | | 3 | - | Waler Beam | | 4 | - | Sheet Pile | | 5 | - | Greased and Sheathed Strand | | 6 | - | Borehole Grout | | 7 | - | Rupture Point | | 8 | - | Borehole Spacer | | 9 | - | Bulbed Strand (Nutcaged) | | A | - | Free Length | | B | - | Bond Length |
|  | | 1 | - | Head Block | | 2 | - | Bearing Plate | | 3 | - | Existing Structure | | 4 | - | Greased and Sheathed Strand | | 5 | - | Borehole Grout | | 6 | - | Rupture POint | | 7 | - | Borehole Spacer | | 8 | - | Bulbed Strand (Nutcaged) | | A | - | Free Length | | B | - | Overall Bond Length |
|
Angle Compensation
| Gusset Arrangement (waler beam / sheet piles) | Shear Tube (existing structure) |
 | - Sub Plate
- Gusset
- Waler Plate
|  | - Sub Plate
- Shear Tube
- Bearing Plate
|
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Removable Strand Anchor System (Temporary Works)
Removable Strand Anchors are typically employed in built-up areas where easement restrictions apply for anchor access, i.e. basement constructions in city centres.
The anchors feature strands which have been specially heat treated at a point just above the bond length, to induce a rupture point. The rupture point is the only point at which the strand will fail when loaded to 220kN.
Removal of the anchor is achieved through the loading of the strand (individually) to failure, at the rupture point. Strand movement is contained by a steel cap at the top of the jack. Following strand rupture all the strands can be withdrawn, with only short sections of strand remaining at the base of the borehole. |  | - Standard Strand
fpu=265kN - Free Length Sheathing
- Rupture Point
(fpu=220kN) - Bond Length Strand
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