A landslide occurs when the driving forces on a soil mass exceed the internal resisting forces of that soil mass. Some of the most commonly used techniques to stop or prevent a landslide include constructing a buttress at the toe, mass excavation to unload the head, draining the slide surface to increase internal strength, and installing tieback anchors, soldier piles, and/or micropiles to provide additional external resisting force.
Tieback anchors provide the most positive and cost effective solution in many circumstances. If the site cannot accommodate mass excavation, or if the soil along the failure surface is difficult to drain, tieback anchors may be the only practical solution. At other times, tiebacks in combination with one or more of the other methods may work best.
Tieback walls constructed to control landslides are designed to increase the resisting forces to a predetermined factor of safety. The wall can be located within the slope to provide the resisting forces in an optimal direction and they can be installed with minimal site disturbance. The tiebacks through the wall are anchored in competent soil or rock behind the slope failure surface. In some situations, the tieback loads are distributed directly to the soil with discrete concrete elements rather than a wall. Often these walls or elements are buried within the regarded slope and the slope is re-vegetated to its original condition.