A technique for forming a bore from a drive pit to a reception pit, by means of a rotating cutting head. Spoil is removed back to the drive shaft by helically wound auger flights rotating in a steel casing. The equipment may have limited steering capability.
Pilot Tube/Guided Boring
Pilot tube - the action of creating the first (usually steerable) pass of any boring process which is later enlarged with additional passes. The pilot tube (first pass) may be used to provide guidance for a guided auger bore. Guided boring is a term applied to auger boring systems which are similar to Microtunneling, but with the guidance mechanism actuator sited in the drive shaft (e.g., a hydraulic wrench which turns a steel casing with an asymmetric face at the cutting head). The term may also be applied to the auger boring systems with rudimentary articulation of the casing near the head activated by rods from the drive pit, or other methods or systems to guide the advancing casing. Guidance may be for grade and/or line.
A steerable system for the installation of pipes, conduits and cables in a shallow arc using a surface launched drilling rig. Traditionally the tem applies to most crossings in which a fluid-filled pilot bore is drilled using a fluid-driven motor at the end of a bent-sub, and back reamed to the size required for the product pipe. The required deviation during pilot boring is provided by the positioning of a bent sub. Tracking of the drill string is achieved by the use of a walk-over system or a downhole survey tool.
A two-stage process in which a temporary ground support system is constructed to permit the installation of the product pipe. The temporary tunnel liner is installed as the tunnel is constructed. The temporary ground support system (liner) can be steel or concrete tunnel liner plates, steel ribs with wood lagging, or an all wood box culvert. Personnel are required inside the tunnel to perform the excavation and/or spoil removal. The excavation can be accomplished manually or mechanically.
A technique for installing steel casings from a drive shaft to a reception shaft utilizing the dynamic energy from a percussion hammer attached to the end of the pipe. A continuous casing support is provided and over-excavation or water is not required. This is a two-stage process.
A system of directly installing pipes behind a shield machine by hydraulic jacking from a drive shaft such that the pipes form a continuous string in the ground. Usually personnel are required inside the pipe to preform the excavation or soil removal process. The excavation can be performed manually or mechanically.
Concrete Box Jacking
Box jacking is similar to pipe jacking, but instead of jacking tubes, a box shaped tunnel is used. Jacked boxes can be a much larger span than a pipe jack with the span of some box jacks in excess of 20m. A cutting head is normally used at the front of the box being jacked and excavation is normally by excavator from within the box.
Drilling completed through rock with any of the methods listed.
* required field.