Existing Ground Anchor Renewal Method

Repair and Maintenance Products
Patent registration number 5674219


In the past, ground anchors with a short extra length of tendon had the problem of being unable to unload or adjust the load. This construction method solves these problems, and is a renewal technology that enables unloading of overloaded anchors that exceed the allowable anchor force and adjustment of loads to higher side for anchors with a significant decrease in load.

As a result, it is possible to recycle existing anchors that have problems and reduce or eliminate the need for new additional anchors, thereby reducing the cost for measures required to ensure the stability of the slope surface. Since it is possible to remove the heads of significantly deteriorated anchors, which is a cause for concern because the anchor heads may protrude onto a public road, etc., this prevents third-party influence beforehand and improves safety and security.

In this construction method, the load is released by cutting the tendon with a special bit, making it safe to work with even the shortest excess length.

Tension and fixing after load release are achieved by using a special fixing tool with an embedded base that was newly developed at the same time, which enables load adjustment and replacement of pressure receiving plate, which were previously difficult after tendon cutting.

Extra length is cut-off

After tendon cutting (load release)

Installation status of special fixings fixtures


  • Even if there is no extra length of the tendon (zero extra length), the load can be released, and the load can be adjusted to the specified load by installing a special fixing device.
  • Since existing anchors can be regenerated after eliminating overloads, the number of new countermeasure anchors can be reduced, and cost of measures can be reduced.
  • Overloaded anchors that are likely to fly out can be removed, preventing third-party impact and improving safety.
  • The working scaffolding is small, about 1 m2 per location, and the work is carried out in a narrow area, so the impact on the service road is small.
  • As the load release works are carried out with light weight drills, it is easy to bring in materials and equipment and workability is excellent.