| Term |
Definition |
|
| Jacking |
The 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. |
| Jacking force |
Force applied to pipes in a pipe jacking operation. |
| Jacking frame |
A structural component that houses the hydraulic cylinders used to propel the microtunneling machine and pipeline. The jacking frame serves to distribute the thrust load to the pipeline and the reaction load to the shaft wall or thrust wall. |
| 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 or renovation of a pipeline, conduit or cable. May incorporate a thrust wall to spread reaction loads to the ground. |
| Jacking shield |
A fabricated steel cylinder from within which the excavation is carried out either by hand or machine. Incorporated within the shield are facilities to allow it to be adjusted to control line and grade. |
| Jacking station (IJS) |
See Immediate Jacking station |
| Jet cutting (jetting) |
(1) A type of Directional Drilling or Guided Boring technique using pressurized fluid jets to provide the soil cutting action. (2) A process using high pressure water to wash out the face of a utility crossing without any mechanical or hand excavatio |
| Joint sealing |
Method in which an inflatable packer is inserted into a pipeline to span a leaking joint, resin or grout being injected until the joint is sealed and the packer then removed. |
| Joints |
The means of connecting sectional lengths of sewer pipe into a continuous sewer line using various types of jointing materials. The number of joints depends on the lengths of the pipe sections used in the specific sewer construction work. |
