Chance® Tie Back Anchors
A.B. Chance has lead the industry in manufacturing of multi-helix screw anchors since the 1950’s. Screw anchors have a definite advantage over other products, with their consistent record of growing use and their strong reputation earned through extensive use in tieback, electrical-utility and petroleum industries.
Ten Advantages to Screw Anchor Application
- Removes uncertainties and costs associated with a grouted anchor when used in loose, sandy soils and low-shear strength clay soils.
- Screw Anchors may be installed with conventional rotary drilling typically used in grouted-anchor tieback construction.
- Installs without drilling or spoils removal, cutting labor and equipment costs by as much as 30%.
- Fast and easy installation (typically takes 20-30 minutes). A rate of 30-40 per day for installing and testing is not uncommon. The designed procedure is based on the popular General Bearing Capacity Equation.
- Since grouted is eliminated, testing is immediately possible following installation.
- Soil strength can be determined by monitoring torsional resistance, which assists in ascertaining anchor load capacities and avoidance in overstress.
- Screw anchors can be withdrawn and reused, making them usable for temporary installations.
- Ultimate tensile capacity of screw anchors can be as high as 200 kips.
- Since there is no need to create an open hole or casing as there is with a grouted anchor, there is no risk of the anchor’s dimensions changing.
- Can be installed in any weather conditions.
Our Tieback anchors can be matched to soil and heavy tension loads in the same way as the Chance® Helical Pier Foundation System Anchors are for compression applications. They’re ideal for building-site preparation, roadways, retaining walls, levees, dams, and revetments. While always competitive, they are most attractive where caving soils otherwise would require casing, and also in high water table areas.
