Case Studies

Project Type
HDD
Location
The Murray River
Length / Hole Diameter
1349 m/ 48 in
Divisions
The Crossing Company, The Tunneling Company

Murray River

Large Diameter Casing Installation

Project Summary

This pipeline crossing project at the Murray River required the installation of large diameter casing and pushed our technical limits.

The Crossing Company used horizontal directional drilling (HDD) to complete this project with a 60” ream pass and a total length of 1349m. The Tunneling Company installed large diameter telescoped casing with a hydro hammer.

Key Challenges

The project included a challenging design with a steep entry angle of 21 degrees and a final 60” ream pass. To ensure the crossing would be successful, a pneumatic hammer and buoyancy control were used during pullback. 

The entry side started with 34m of 96” casing, followed by 70m of 84” casing and 107m of 72” casing. The earth was pulled out between each round of casing, leaving an opening for the pilot tube. After the pilot tube was installed The HDD Company reamed back and forth, eventually creating a 60” hole that could hold the 48” gas line. 

Casing on the exit side of the project included 40m of 84” and 60m of 72” pipe.  

Buoyancy control was utilized by The Crossing Company to help reduce expected theoretical pull forces. The product pipe was filled with water to help mitigate the high pull forces that we typically expect on long crossings with large diameter product pipe. 

While using a pneumatic hammer during pullback is rare, it was also utilized to help overcome the higher than anticipated pull forces and made this project an overall success!

Services Provided

Horizontal Directional Drilling, Pipe Ramming

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