Definition - What does Jacking Shaft mean?
Jacking shaft is an excavation on a planned pipeline or conduit installation site from which equipment needed for directional boring or tunneling is launched. In trenchless technology jacking shaft plays a very important role in the installation process. Jacking shaft helps overcome obstacles on the pipeline route such as roads, railway lines, canals, and rivers. The jacking shaft used in pipe jacking applications is usually used for installation of large diameter pipelines but can also be used for short crossings. Sometimes intermediate jacking stations (IJS) are used for longer lengths of installation.
Trenchlesspedia explains Jacking Shaft
Trenchless methods like pipe jacking, and microtunneling require jacking shafts in which powerful hydraulic jacks simultaneously excavate and install pipes through the ground providing a structurally sound, and watertight, finished tunnel. A metal shield is sometimes used to protect the pipe from damage during the jacking operation. Thrust pit at entry point and reception pit at exit point is constructed at the manhole positions. A thrust wall or structural framework is constructed in the thrust pit to provide a reaction system for the jack. The jacking shaft houses all the necessary equipment needed to complete the installation process including space for crew, and slurry separation chamber.