Tiebacks
Tiebacks (or Anchors) are engineered tensile elements used to provide temporary or permanent lateral support for earth retention structures such as sheetpile walls, soldier pile and lagging walls, secant pile walls and slurry walls. Tiebacks are the preferred method of lateral support when congestion within the limits of the excavation must be minimized.
Tiebacks generally consist of a central steel bar (or strand tendon) surrounded by an annulus of grout. They typically derive their geotechnical capacity through side friction between the grout and surrounding soil or bedrock. The construction process varies depending on project specific conditions, but generally consists of: 1) drilling a hole into sound soil or bedrock (using casing as necessary), 2) inserting the central bar/tendon, 3) filling the hole with grout, 4) withdrawing the casing to create a bond zone between the grout and surrounding soil or bedrock, and 5) tensioning the bar/tendon in preparation for the structural connection with the excavation support wall.
Helical Piles can be used as Tiebacks/Anchors in certain soil conditions.
