DYWIDAG Removable Strand Anchors
DYWIDAG Anchor Systems
DYWIDAG removable strand anchors are based on a multi-stage anchor with a compression unit at the distal end of each stage. The full length of the anchor, other than the compression unit, is de-bonded. When the anchor is stressed, the compression unit reacts against the underside of the grout column, putting it into compression: hence the term “compression unit”.
At the base of each compression unit is a rupture point formed from a strand fixing with a known failure load. Stressing the anchor in excess of that failure load causes the strand to break free of the compression unit. It can be removed, leaving only the small compression unit in the ground.
The demand for these anchors in urban areas is increasing, based on the limited easement restrictions imposed by adjacent landowners and the potential for tunneling below urban environments. Removable strand anchors can be supplied to a variety of specifications and can be used for excavation support as an alternative to propping. Anchoring provides the necessary support to excavations, but without reducing the working space or available headroom on site.