Case Studies

Project Type
UTILITY PIPELINE
Location
ALBERTA, CANADA
Length / Hole Diameter
911 m (2,989 ft)/ 457 mm (18 in)
Divisions
The Crossing Company

DEERFOOT TRAIL PIPELINE

12-LANE FREEWAY CROSSING

Project Summary

One of the most daunting challenges in any urban construction project is to successfully complete the project while causing minimal delays and inconvenience to citizens.

When our customer needed to install a 305 mm (12 in) replacement pipeline under 12 lanes of traffic at the city’s second-busiest intersection (averaging 238,000 vehicles/day) a prolonged shutdown was out of the question.

The line was placed at the intersection of Deerfoot Trail and 17th Avenue SE (one a provincial highway, the other a city thoroughfare). The Crossing Company employed a heavy rig to drill a pilot and install the line across the north and southbound lanes, two exit ramps and an exit loop. The same rig was used to install 55 m (180 ft) of 610 mm (24 in) casing.

Key Challenges

Normally, surface coil is laid above the ground along the drilling path, sending an electronic signal to guide the drill. Due to the traffic, another solution was required. The Crossing Group employed a series of strategically-placed beacons to communicate with the steering tool below the surface. The project was completed within one month. The only disruption was a one-day Sunday closure of 17th Avenue SE while the product line was being pulled across the roadway, and into the prepared borehole as the final stage of installation.

Additionally, a site-specific plan with road control measures was required to mitigate any potential issues related to trucking on these high-traffic city roadways.

The Crossing Company completed the project under time and under budget – while keeping traffic flowing.

Services Provided

HORIZONTAL DIRECTIONAL DRILLING AND SURFACE CASING

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).

The Crossing Group - The Tunneling Company - Tunnel Boring - Pipe Jacking - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

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).

The Crossing Group - The Tunneling Company - Slip Boring - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

DOWN THE HOLE HAMMER

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.

The Crossing Group - The Tunneling Company - Down The Hole Hammer - DTH - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

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.

The Crossing Group - The Tunneling Company - Guided Boring - Trenchless Construction - Tunneling - Augering, Boring & Pipe Ramming

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).

The Crossing Group - The Tunneling Company - Pneumatic Pipe Ramming - Tunneling - Augering, Boring & Pipe Ramming