Jacking Loads

See Jacking ForceThe total force required to overcome the face pressure component and the frictional resistance component along the pipe so as to allow forward movement of the MTBM and the trailing pipe string..

Jacking Pipes

Pipes designed to be installed using pipe jacking techniques.

Jacking Pit

The excavation that the machinery is set into to install a casing or tunnel. In years past, it has also been known as a “Glory Hole.”

Jacking Shaft

Excavation from which trenchless technology equipment is launched for the installation of a pipeline. The jacking shaft may incorporate a thrust wall to spread reaction loads to the ground and an entry ring to control inflows of groundwater and soil at the portal.

Jacking Shield

A fabricated steel cylinder from within which the excavation is carried out either by hand or machine. An articulated steering section and steering jacks are incorporated into the shield to allow it to be adjusted so as to control line and grade. The term is associated with traditional tunneling.