Rock Anchor
Rock anchor are post-tensioned tendors installed in drilling holes for which at least the entire bond length is located in rock. The anchor force is transmitted to the rock by bond between the grout body and the rock. Rock anchors can remains unbounded in the free stressing length allowing the anchor to be checked and re-tensioned at any time. In such cases, adequate corrosion protection for the stressing anchorage and the free stressing length must be provided.
- Resist external and uplift forces caused by wind or seismic event.
- Tie Back retaining walls.
- Stabilize the stability of dreams or large bridge foundation.
Although there is no theoretical limit to the capacity of Stand anchor, practical consideration such as drill hole size and the availability of material handling for equipment limit the size of an anchor to 91 0.6"(15.02 mm) dia. Strands in most cases. Larger anchors are manufactured, but practicality & economics of their use should be truly evaluated more they are incorporated into a design.
Techno Infra Stands Anchor system may be stressed to the allowable limits of the American concrete Institute Code No. ACI 318. The maximum jacking stress(test load) for anchor shall not exceed 0.80 fpu of the prestressing steel. The lock off load depends on the specific requirements of the projects. Initial load transfer force at lock-off shall not exceed 0.70 fpu.
Wedges shall always be seated at a load that is greater than 0.50 fpu. The final(working) prestress level is dependent on
- Application
- Installation procedure
- Stressing Sequence
- Rigidity of the structural System
- Seating losses
