Anchors are stabilization and support elements that transfer tension loads using high-strength steel bars or steel strand tendons.

Common Uses

  • Resist uplift forces
  • Part of a permanent or temporary retaining wall

Technical Details

Rock Anchors come in many shapes and sizes. Post-tensioned rock anchors actively transfer loading between the anchored structure and its underlying rock mass, thereby lowering the structure's centre of gravity. Passive rock anchors have high capacity to resist event-induced tensile loading, such as loading arising from periodic seismicity or seasonal buoyancy. Importantly in the case of post-tensioned or passive rock anchors installed to retrofit existing dams, the rock anchors also enhance the dams' resistance to sliding and overturning.

A rock anchor consists of a tendon and an anchorage. The tendon can consist of one or more solid steel bars, a single hollow bar, or a bundle of several high tensile steel strands. The tendon always features a bond length, and often features a free stressing length, over which a debonding mechanism or process ensures that the tendon is free to elongate without obstruction during tensioning. Drilling, grouting and tension testing are the three principal components of any rock anchor construction project. In the case of post-tensioned rock anchors, every installation is at least proof-tested by applying tension equal to 133% of the anchor's design loading.

Rock and soil anchors are designed to withstand lateral and uplift forces and offer an economical solution for temporary deep excavation support systems. Multiple rows of anchors can be used to provide the required support. Other applications include tiedowns for dams, bridge abutment support, buoyancy control in structures, or other applications to resist tension loads. This technique is used in excavation support, slope stabilization and foundation upgrading/rehabilitation.

Keller has installed rock anchors on projects all across Canada, including many dams. We are a full-service rock anchor contractor; we complete every component of the construction process, including drilling, consolidation grouting, water tightness testing, post-grouting, installation, and performance and proof tensioning.