What is "tieback"

n. 1 A loop of cloth, cord, etc., which is placed around a curtain to hold it open to one side. 2 (context journalism English) A newspaper rewrite or short synopsis of the information presented in the original story. in order to refresh the memories of readers who saw the old story and to update new readers.

n. a device (as a decorative loop of cord or fabric) for holding or drawing something back; "the draperies were drawn to the sides by pullbacks" [syn: pullback]

Tieback may refer to:

• Tieback (geotechnical), a method of supporting retaining walls
• Tieback (subsea), a connection between a new oil and gas discovery and an existing production facility, such as the Brae oilfield
• Curtain tie-back, a kind of decorative window treatment

A tieback is a horizontal wire or rod, or a helical anchor used to reinforce retaining walls for stability. With one end of the tieback secured to the wall, the other end is anchored to a stable structure, such as a concrete deadman which has been driven into the ground or anchored into earth with sufficient resistance. The tieback-deadman structure resists forces that would otherwise cause the wall to lean, as for example, when a seawall is pushed seaward by water trapped on the landward side after a heavy rain.

Grouted tiebacks can be constructed as steel rods drilled through a concrete wall out into the soil or bedrock on the other side. Grout is then pumped under pressure into the tieback anchor holes to increase soil resistance and thereby prevent tiebacks from pulling out, reducing the risk for wall destabilization.

Helical anchors are screwed into place. Their capacity is proportional to the torque required during installation. This relationship is in accordance with the equation Qt = kT where Qt is the total tensile resistance, k is an empirical constant and T is the installation torque. These anchors are installed either for small loads in short sections or for larger loads and in long continuous lengths.