A.B. Chance Tie Backs are similar to the helical pier, except the member acts in tension verses compression. The chance tiebacks are used to provide temporary or permanent support of sheet piling, concrete walls, timber lagging and for tie down applications.
When the screw anchor is placed in the soil, it acts as a bearing device. This is the fundamental difference compared to a grouted anchor, which is reliant on frictional capacity generated between the soil and grout.
An advantage of the A.B. Chance system is that the installation is much faster than grouted anchors. Also, no drilling is required, and no spoils are removed. Since grout is not used, the anchor may be immediately loaded.