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.

Jacking Station (IJS)

See Immediate JackingThe actual pushing of pipe or casing in an excavated hole. This is usually done with hydraulic cylinders (jacks), but has been done with mechanical jacks, air jacks and just about anything else that man could imagine. Station.

Jersey Barrier

See K-RailA modular concrete or plastic barrier employed to separate lanes of traffic. Also known as Jersey Barrier..