What Are Ground Anchor Heads?

Ground anchor heads connect a ground anchor’s tendon to the structure it supports. Positioned at the exposed end of the anchor, they secure the steel bar or strands against a bearing arrangement on a wall, beam or foundation.

The head forms one part of the complete anchoring system. Below ground, the tendon extends to a bonded length, where grout transfers forces into suitable soil or rock. Each component contributes to a continuous connection between the structure and the ground.

Anchor heads feature in ground engineering works where structures need restraint against lateral movement or uplift. Infrastructure and rail applications include anchored retaining walls beside roads, bridge approaches, cuttings and station excavations. In marine settings, they provide connections for quay wall strengthening and dry dock restraint.

Residential, commercial and institutional projects may require ground anchors to support basement excavations or resist groundwater uplift. Applications range from apartment buildings and underground car parks to hospitals and university facilities. Within the energy sector, anchoring systems can support dam strengthening and provide foundation restraint for towers and other generating infrastructure.

Where anchors support sheet piling or piled retaining walls, heads may bear against a waling beam that distributes the anchor forces across the structure. The arrangement must suit the supporting structure and tendon direction.

The assembly varies between bar and strand systems. Its principal components and associated fittings can include:

• Anchor nut: secures a threaded bar against the bearing assembly.
• Wedges and anchorage block: grip individual strands in a strand anchor system.
• Bearing plate: spreads concentrated force into supporting steelwork or concrete.
• Angled seating: accommodates inclined tendons and provides the required bearing contact.
• Protective cap and seals: shield exposed components from moisture and contamination.
• Load-monitoring equipment: measures tendon force where ongoing observation is specified.

The structural components hold and transfer load; protective and monitoring fittings support durability and inspection. Their specification depends on the selected anchoring system.

For a prestressed ground anchor, stressing begins once the grout and supporting structure have achieved the specified strength. A hydraulic jack tensions the tendon while the bearing assembly resists the load.

Loading follows a defined testing procedure. Force and tendon movement measurements help assess whether the installed anchor meets its acceptance criteria. Testing considers the performance of the complete anchor system, including the bond between the anchor and the surrounding ground.

Following acceptance, the tendon is secured at the specified lock-off load. Nuts or wedges retain this force when the jack is released. Allowance for seating movement forms part of the stressing procedure.

The results are recorded before the completed anchor head receives its specified protection. Some systems allow subsequent load checks or adjustment, but the original detailing must include this capability.

The transition between an exposed head and the buried tendon needs continuous corrosion protection. Depending on the system, this may involve sealed caps, protective compounds and sleeves connected to the tendon’s protective sheath.

Water entry, damaged seals or deterioration around the bearing surface can affect long-term performance. Inspection arrangements should reflect the exposure conditions and intended service life. Coastal locations, for example, require consideration of salt exposure.

Planning protection and maintenance access alongside structural design helps keep this small but significant connection serviceable. Throughout its service life, the anchor head remains the connection between the buried ground anchor and the structure it restrains.