Drill-Tech - Tiedown Anchors
Drill Tech and our staff of professional engineers have been involved in some of the biggest, deepest, and most high profile tiedown anchor projects in the United States, including the retrofit of the Golden Gate Bridge.
Tiedown anchors provide resistance to vertical forces generated by earthquakes, overturning, and hydrostatic forces. They consist of a high strength steel tendon (bar or strand) grouted into drilled holes and tensioned against a structural anchorage.
The bonded portion of a tiedown is the length of the tendon that is bonded to the anchor grout and transmits the applied tensile load into the ground. The unbonded length is the portion of the tendon that is free to elongate elastically and transfer the resisting force from the bond length to the anchorage. Tiedown anchors are corrosion protected with epoxy coating or corrugated plastic sheathing to provide a permanent service life.
The steel tendons have a free stressing (unbonded) length and a bonded length. The bonded portion of a tiedown is the length of the tendon bonded to the anchor grout and transmits the applied tensile load into the ground. The unbonded length is the portion of the tendon that is free to elongate and transfer the resisting force from the bond length to the anchorage.
Tiedown anchors are corrosion protected with epoxy coating or corrugated plastic sheathing to provide a permanent service life.
- New bridge and building foundations
- Seismic retrofits of existing structures
- Existing dam and spillway stabilization
- Uplift resistance for foundation slabs below the water table