When a retaining wall itself does not provide sufficient stability, horizontal or angled holes are drilled into solid earth or rock. By setting and tensioning anchors, the stability of the wall is increased and this increases the allowable depth of the excavation. A full-length hole is drilled through the soil and into the bond zone in soil or rock using casing if necessary. A threadbar or strand tendon anchor is inserted into the hole and the hole is filled with high-strength grout.
The anchor head is then connected to the structure requiring the support and tensioned to the designated load.