Active and Passive Anchors

Active and Passive Anchors

Ground Anchors can be classified as active and passive anchors. An active anchor is post/pre-tensioned before it takes up the load, which prevents distortion of the structure. The tendon is usually made of pre-tensioned steel cables. Post-tensioned rock anchors actively transfer loading between the anchored structure and its underlying rock mass, thereby lowering the structure's centre of gravity.

A passive anchor is tensioned by the structure itself applying load to it. It does not usually have a free length of tendon. Generally, the tendon is made of steel or an alloy material.  Passive rock anchors have high capacity to resist event-induced tensile loading, such as loading arising from periodic seismicity or seasonal buoyancy.