When CT Civil recently took on the challenge of installing 53m of steel carrier pipe beneath the State Highway in New Zealand, it relied on TRACTO’s GRUNDORAM TAURUS pipe ramming system to get the job done.
Established in 2008 as Concrete Treatments NZ Limited, CT Civil initially specialised in drainage rehabilitation for the municipal sector.
Over the past five years, the company has shifted to focus on broader civil construction, reflecting the growing demand for its expertise in tunnelling, trenchless pipe installation, bentonite and slurry mixing and support, as well as dewatering and desludging.
In 2022, the company rebranded to CT Civil, highlighting its expanded focus on civil construction and engineering.
With over 20 years of tunnelling experience, Bishop and the CT Civil team have delivered challenging projects in unique environments, maintaining a commitment to safety, quality, and client collaboration.
The 53m section, constructed using trenchless pipe ramming, was part of a larger project to install a new sewer underneath one of the North Island of New Zealand’s major arterial roads, SH.
CT Civil was contracted to complete construction of the trenchless section of the project by principal contractor Brian Perry Civil.
A trenchless method which is becoming more common in New Zealand and Australia, CT Civil Director of Operations Leigh Bishop said the ground conditions played a crucial role in the decision to use pipe ramming.
“The ground was very unpredictable,” Bishop said.
“We encountered large cobbles, timber, rail sleepers, concrete, and general fill materia.
“Pipe ramming was the best solution for ensuring we could navigate those obstacles and reach the other side of the highway.”
The area presented additional challenges, with an old creek running through a gully that had been filled in over time.
“We needed access to the face of the pipe to deal with obstructions as we encountered them on the drive, and pipe ramming allowed us to do that efficiently.”
Using TRACTO’s GRUNDORAM technology, CT Civil achieved an impressive result, with the alignment of the pipe exiting within 30mm of the target, which was crucial to the success of the installation.
“The accuracy was remarkable given the ground conditions, and we made some small adjustments to the cutting shoe,” Bishop said.
The GRUNDORAM system is renowned for its accuracy, along with a list of other features, including strength, versatility and power.
The dynamic steel pipe installation method applied by the machine enables the economic installation of casing or product pipes up to 4m diameter in soil classes 1−5.
This includes installations underneath roads, railway tracks and rivers over lengths of up to 100m.
As the machine progresses through the ground it can navigate through the toughest of geologies and conditions.
CT Civil identified multiple challenges present at the job site during the design and planning phase of the project, including foreign objects and a high water table.
The contactor removed spoil by hand throughout large sections of the installation from within the casing.
“This reduced friction inside the pipe and allowed us to deal with obstructions more effectively,” Bishop explained.
“If the pipe stopped moving, we could excavate to the face and use different methods to remove or work around the blockage.”
Bishop said pipe ramming offers a number of benefits over other forms of trenchless construction, especially when it is backed up with the support of TRACTO’s local and international team of experts.
“The 1.65m diameter carrier pipe, with a wall thickness of 25mm, required 40 hours of welding per joint, which was a significant undertaking,” said Bishop.
“But with the support of the team at TRACTO Australia we were able to navigate these challenges and deliver a successful outcome for the principal contractor and asset owner.”
TRACTO is one of the world’s leading trenchless technology companies, providing smart no-dig solutions for underground infrastructure projects worldwide, including energy, water and communications installations.
TRACO sales manager Dan Toms said the company has seen an increase in the popularity of pipe ramming in Australasia.
“Pipe ramming is one of the most versatile forms of trenchless construction,” he said.
“It can also be used for what we call ‘HDD assist’, meaning the GRUNDORAM systems can be used to install a conductor barrel casing, providing a favorable starting point and friction free pullback section for directional drilling in difficult soil conditions.”
“The TAURUS is part of an extended range of pneumatic pipe ramming tools we offer to the local and international market.”
“There are some installations that just wouldn’t be possible to complete using other technology, including this Wellington project.”
For more information, visit tracto.com/au
This article was featured in the February edition of Trenchless Australasia.
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