Tunneling – Augering, Boring & Pipe Ramming
The tunneling process is extremely well suited for applications that involve short crossing distances, and situations where the project footprint does not allow for an entry and exit angle (as required in horizontal directional drilling).
Our technologies are used for the installation of all types of utilities under roads, railways, rivers, congested areas, environmental sensitive areas, alternates to deep open cuts and many other applications. Ground water, unconsolidated formations, subsurface debris and restricted workspace are all challenges that tunneling can be used to overcome. With tunneling, there are few limitations concerning diameter.
Our team has developed a reputation for excellence in tunneling, utilizing a variety of established tools and techniques – including proprietary technologies.
Open the links below to learn about these tunneling methods and to see how each process works.
EXPLORE OUR TUNNELING METHODS (WITH ANIMATION)
- Horizontal Auger Boring
Horizontal Augering equipment is utilized to install 305 mm to 1.8 m (12 in to 72 in) diameter steel casings. Our Horizontal Augering machines are frequently employed in cleaning out casings and culverts where dirt or other obstructions are restricting or blocking flow.
Horizontal Augering can also be used in conjunction with a Small Boring Unit (SBM) for boring 610+ mm diameter holes (24+ in) through solid rock, which is done in unison with our disc cutter heads.
- Pneumatic Pipe Ramming
Pipe Ramming is used in a wide variety of soil types including gravel, cobble or sand. A pneumatic hammer is attached to the back of the casing pipe and driven through the material at any angle: from horizontal to vertical. The material is cleaned out of the pipe using an auger boring machine. Pipe Ramming methods are used for pipe diameters of 305 mm to 3.6 m (12 in to 144 in).
- Guided Boring
A Guided Boring Machine (GBM) is used to install 305 mm to 3.6 m diameter pipe (12 in to 144 in) with grade and alignment precision. It is commonly used for installations 50 m to 150 m in length (164 ft to 492 ft) or when line and grade accuracy is critical in displaceable soil. Our GBM is extremely versatile and our customers continually approach us with new applications.
The pipe installation involves a two-step process where launch and reception shafts are strategically located to minimize surface disruption. A pilot tube with a theodolite guidance system is then pushed through the ground at the precise grade and alignment specified in the design into the reception shaft. A reaming head is welded to the pilot tube and the casing and the pilot tube is used as a guide to install casing. The GBM can be used in conjunction with auger boring or pipe ramming methodologies.
- Down the Hole Hammer (DTH)
A pneumatic hammer is attached to the inside edge of the casing. The front of the DTH breaks cobles, boulders and even solid rock into small pebbles or dust. The spoil makes its way through the hammer and into the casing, where it is removed by airway augers.
- Slip Boring
A boring technique commonly used for installing oil & gas pipelines ranging from 51 mm to 1067 mm (2 in to 42 in) in diameter without leaving casing in the ground. Product pipe is welded to steel casings and either pushed or pulled through the ground in sections. The casing is cut off and removed, leaving just the product pipe. Maximum installation length is 150 m (492 ft).
- Surface Casing (Conductor Barrel)
Surface casing is required for horizontal directional drilling, and serves as a starter casing to guide the drill. It is installed through an overburden at the entry point. Steel casing is hammered into the ground at the required angle (ranging from 9° to 30°), and spoil is removed by an auger. Casings typically average 30 m to 50 m (98.5 ft to 164 ft), and can reach a recommended installation length of 200 m (656 ft).
- Tunnel Boring / Pipe Jacking
Tunnel Boring and Pipe Jacking Systems are used to hydraulically install underground pipelines up to 4.2 m (168 in) in OD range within strict alignment and grade tolerances. The likelihood of settling or sloughing is very low. Wheel machines are equipped with various cutter heads and sand shelves. A closed-face attachment is available for boring in unstable ground conditions. This versatile system can be easily adapted to work with any jacking pipe, in any pipe joint length. It can accommodate a wide range of pipe diameters.
Tunnel Boring Machines are used to excavate tunnels with a circular cross section through a variety of soil and rock strata. They can bore through hard rock, sand, and almost anything in between. Tunnel diameters can range from 1 m and exceed 15 m (3 ft to 49 ft).
Microtunneling is a type of ‘remote control pipe jacking’ where a microtunnel machine is controlled remotely from a control shack. The cutter head matches the pipe diameter size for installation and the crushed materials are transferred through a ‘slurry’ mixture which is pumped into and out of the pit.
This method is most commonly used in unstable ground conditions or under the water table.