Trenchless Technology & Tunnelling

Navigating underground infrastructure environments today can be a daunting task. Geological conditions, challenging access, obstructions, traffic and crowded multi-utility spaces are just some of the many factors to consider.

With over 40 years of experience in trenchless technology, at Marathon Underground we’ve developed a deep understanding of what’s required to make each project a success. From tunnelling under highways, to pipe jacking under railways lines to directionally drilling under rivers and lakes, we have the full range of equipment and experienced staff to complete any trenchless project.

From coast to coast across Canada, we’ve completed projects over 1000 metres long and up to 8 feet in diameter. Our Trenchless Technology group offers all of the latest trenchless technologies and solutions, including:

Horizontal Directional Drilling (HDD): For long runs that require a curved path to achieve a crossing under a large body of water, railway or road, HDD offers a steerable system that remains above ground. A small pilot hole is drilled initially, followed by a second drilling head used to make the appropriate sized hole for the product pipe.

Microtunnelling: This trenchless construction method is excellent for situations where a high degree of accuracy is needed. A launching shaft and an exit shaft are required with the Microtunnel Boring Machine (MTBM) being pushed through the tunnel with a hydraulic jacking system. It is a closed loop system that cycles spoils back through a slurry machine on the surface for separation and haulage. The system is controlled above ground, is laser guided and steerable to keep the machine on track and achieve supreme accuracy.

Horizontal Earth & Rock Auger Boring: This is the most common trenchless method. A launching and exit shaft are required with a jacking station pushing an auger through the ground. Spoil is then removed back to the launching shaft by auger flights rotating in a steel casing.

Pipe Ramming: Installing steel casing (pipe) from a launch shaft to an exit shaft utilizing the force of a percussion hammer attached to the end of the pipe. This is best used in situations where settlement is a concern; for example, under railway lines.

Pipe Jacking: A hydraulic jacking system pushes the product pipe directly from the launching shaft to the exit shaft. This system can push pipe for a new installation or push a larger diameter pipe over a smaller diameter pipe (a technique known as “pipe swallowing”).

Marathon also has the capabilities to perform speciality trenchless services for the pipeline industry, such as:

• Pipe bursting is a trenchless method of replacing buried pipelines (such as sewer, water, or natural gas pipes) by expanding the existing pipe (bursting) so that the large trailing pipe can follow.
• Slip lining which is completed by installing a smaller carrier pipe into a larger host pipe, grouting the annular space between the two pipes, and sealing the ends.
• Slip boring which is used to install pipe without leaving the casing in the ground.

We also have trenchless methods to support the mining industry, including:

• Raise boring which sees a small-diameter hole (known as a “pilot hole”) drilled to the level required followed by a reamer head of the required diameter attached to the drill string and raised back towards the machine on the surface.

With a complete range of equipment and geotechnical expertise inhouse, we can collaborate with your design team and find the most cost-effective solution to your trenchless project.