Trenchless helps care for NZ water sector

Trenchless Australasia sat down with Watercare’s John McCann to ask what sparked the company’s interest in non-conventional construction methods, the Watercare’s core values when it comes to infrastructure decisions and the changes in NZ’s water sector as a whole.

Mr McCann is a Projects Manager in Watercare’s construction delivery team where he heads up a team of project managers focused on the successful delivery of water, wastewater and treatment projects across the Auckland region.

The delivery of these projects is often achieved with trenchless technologies, which Watercare has been implementing in its construction works for more than 20 years, often using horizontal directional drilling (HDD) and microtunnelling due to their versatile and cost-effective nature compared to traditional trenching methods.

“The unique Direct Pipe® tunnel boring technology has created more possibilities for installing pipelines at various depths and in different geology,” says Mr McCann.

“We used this methodology for the first time in NZ and Australasia 18 months ago. We are currently close to completing our second wastewater ocean outfall pipe installation using this technology.”

The Direct Pipe® trenchless technique was used on the Army Bay Ocean outfall project by Watercare.

Growing benefits

Mr McCann says Watercare first began using trenchless technologies due to the community benefits they could provide.

“It means we can build below Auckland’s busiest commercial areas, railways, motorways and major regional arterial routes carrying thousands of commuters every day with minimum disruption,” he says.

Watercare has recognised there are even more benefits that come from trenchless technology, such as minimal environmental impact and carbon emission reductions.

“Pipe jacking and microtunnelling are some of the safest and most environmentally friendly underground construction processes,” says Mr McCann.

“Last year we announced our 40:20:20 vision for our infrastructure delivery program. The aim is to reduce carbon in construction by 40 per cent, injuries in construction by 20 per cent year on year, and infrastructure program costs by 20 per cent by 2024. These methods will help us to meet these goals.”

Watercare’s organisational vision is to be ‘trusted by its communities for exceptional performance every day’.

“When it comes to building or upgrading infrastructure, we have to do this in a reliable and cost-effective way so that we can accommodate growth while maintaining service standards and keeping our charges to a minimum,” he says.

“Many factors are considered in the decision-making process including the buildability, potential disruption, public safety and cost.”

A global task

Watercare often uses local contractors and technology from NZ and Australia and also uses innovative technologies from around the world.

“The Central Interceptor wastewater tunnel project is a good example where international experience and technology is being leveraged to help service new growth while also cleaning up the environment,” says Mr McCann.

The Central Interceptor is being constructed by the Ghella Abergeldie Joint Venture (GA), founded in Italy and Australia respectively. Watercare says GA has more than 150 years’ experience with tunnelling and wastewater projects of this size across the globe, making it the suitable contractor to create the super-sized wastewater tunnel that will reduce overflows.

Change for the future

With its reputation of consistent innovation, Watercare recently developed an enterprise model to build and deliver water and wastewater infrastructure more effectively.

Building on its 40:20:20 goal by 2024, the company is working collaboratively with selected contractors to plan and deliver a program of work rather than discrete projects, which will help drive investment and innovation in the industry while also improving cost efficiency.

Mr McCann says the future of NZ’s water sector may see many changes, as 2020 saw Auckland hit by the worst drought on record off the back of a further drought in 2019. Additionally, climate change is likely to deliver more extreme dry periods punctuated by more intensive rainfall events.

“The next decade will continue to see significant investment in the water and wastewater sector with opportunities for innovation that allow cost-effective infrastructure to continue being built while minimising disruption and effects on communities,” he says.

This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Watercare website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

Rob Carr TBM

Driving through dirt and rocks

While the situation on Melbourne’s streets continues to evolve, below the surface Rob Carr grapples with its own challenges, using its microtunnelling expertise to overcome any obstacle.

The sewer network in Melbourne’s CBD is approximately 120 years old and is relied upon by a rapidly expanding population, with Melbourne’s entire population now closing in on 5 million. To ensure this vital network can cope with the needs of the reliant homes and businesses, City West Water (CWW) appointed civil construction and tunnelling expert Rob Carr – in association with design partner SMEC – to complete the Lonsdale Street Sewer Upgrade.

The project is the second stage of a four-stage strategy to install a secondary 900 m long sewer line under Lonsdale Street, with Rob Carr to deliver a DN 1400 glass fibre reinforced plastic (GRP) sewer line using a microtunnel boring machine (MTBM) for its construction.

After launching the MTBM from its 23 m deep launch shaft on William Street in early 2020, Rob Carr completed its first drive of approximately 550 m. The machine has now been turned around and commenced jacking on the second line, which is to be 350 m long.

Rob Carr is also simultaneously completing a new 23 m tunnel into Elizabeth Street using a hand jack, which will be tied into an existing manhole at that location.

The MTBM breaks through underneath Lonsdale Street.

Above the surface

While the tunnelling operations continue to run 24 hours a day, six days per week below the surface, Melbourne’s above ground situation continues to be impacted by the COVID-19 pandemic. After briefly easing restrictions, several virus outbreaks in Victoria have forced residents to return to strict lockdowns and once again increase prevention measures.

Rob Carr and CWW have been adhering to all coronavirus prevention guidelines onsite, allowing the project to continue running at full power. Border closures have forced some interstate workers to remain in Victoria, but Rob Carr Construction Manager Andrew Scarr says everyone involved has been able to deal with the changing conditions.

“It has an effect, but we have managed to work around any of those challenges,” he says.

“Later this year we hope to complete the line we are constructing at the moment, tie into the manhole on Spencer Street and complete the manhole at the launch shaft.

“The project has had its challenges, but we’ve continued to move forward and are steadily delivering these sewer upgrades.”

Rob Carr aims to complete its works later in 2020.

This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Rob Carr website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

Bothar’s critical seaway project a success

Over the past 20 years, the Gold Coast has seen unprecedented growth causing its existing excess recycled water release infrastructure to approach its capacity and capability. Thanks to the work of the Bothar team, the city’s recycled water infrastructure is now future proofed for the expected population increase over the next two decades.

Project specification

The installation of the new pipe was completed using a Herrenknecht AVN2000AB Tunnel Boring Machine (MTBM), with Bothar’s Project Manager Kieran O’Connor saying this could be the longest subsea microtunnelling drive completed in the southern hemisphere.

Bothar was also responsible for the temporary works design and construction of launch and retrieval shafts required for pipe jacking operations. The launch shaft at Quota Park in Biggera Waters was 26 m deep and 12.5 m diameter secant piled construction with the reception shaft – a 7.5 m diameter, 26 m deep pre-cast segmental sunk caisson – situated at South Stradbroke Island.

Mr O’Connor says Bothar was engaged to be the project’s specialist subcontractor on this critical seaway project.

The project’s first MTBM ready for launch.

First stages complete

In May, Bothar’s first MTBM resurfaced from its 1,385 m subsea crossing underneath the Gold Coast Broadwater, signalling the completion of the project’s first stage of tunnelling. Over the coming months, an AVN1500 – the project’s second MTBM – will be used to tunnel between Quota Park and O’Connell Park.

Both MTBM’s were manufactured by Herrenknecht and have been sourced from Bothar’s extensive international fleet of Herrenknecht machines.

Risk mitigation technology Mr O’Connor says the decision to use microtunnelling was born out of a need for risk mitigation considering the inherent technical, safety, environmental and community risks associated with the complex and challenging tunnel.

“Microtunnelling provided the optimal balance of innovation and risk mitigation,” he said.

“The subsea crossing was constructed underneath the seabed of an environmentally protected area of Moreton Bay providing for its continuous use by the local community for boating, fishing and recreational activities.”

In addition to the challenging tunnelling task, the hurdle of COVID-19 also arose during the project. To overcome social distancing restrictions and complete its essential project, Mr O’Connor says Bothar implemented strict protocols for its staff, including daily temperature testing and hygiene practices.

Bothar’s dedication to mitigating risks both to the environment and to its own workforce during the project demonstrates its commitment to finding a successful solution regardless of the challenges faced.

This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Bothar Boring website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

The edge over tough microtunnelling projects

As the trenchless industry continues to expand across Australia, site conditions that make microtunnelling projects seem high risk or impossible are creating long-term limitations on the work available and, in turn, damaging the industry’s growth. Edge Underground Managing Director Stuart Harrison says at least half the projects the company undertakes are those no other contractor wants due to concerns over project success.

“Part of the reason that we take on these jobs is because we’ve got a belief in our own ability, and the equipment that we run,” says Mr Harrison.

“But also, we feel like it is somewhat of a responsibility to show people what is possible. At the end of the day if contractors keep turning around saying, ‘Oh no, there’s a problem, you need to dig this up’, or say straight up that the project is going to be too difficult, we’re essentially cutting down the scope of our own industry.

“We certainly don’t look at it that way. We look at every job as being achievable, it’s just a matter of finding a way and a means to complete that job successfully and achieve that outcome. We go out there with a good attitude and with state-of-the-art equipment and understand all the different aspects of a job and the complexities, and still find a way to get it done.”

Equipment is key

In all microtunnelling projects – although especially in high risk conditions – having the right equipment is critical to success.

“One example of this was a project in Donnybrook, Victoria, which no other contractor wanted to take on due to the ground conditions (a combination of extreme hard rock with seams of clay and fractures), which had a high risk of wedging occurring,” says Mr Harrison.

To counteract this problem, Edge Underground used the AXIS laser guided boring system, allowing the team to retract the drill head to complete a pilot line and inspect the ground to confirm conditions. In doing so, Edge Underground did not go into the project with incorrect or partial geotechnical information and, instead, could configure the reaming tool to best suit the pipe jacking conditions required.

Mr Harrison says this feature means if conditions do change again further down the installation, the drill head can be retracted and changed out to something more suitable so drilling can recommence from the same spot. This capability is not found in other machines, which increases the project’s risk as it would require the drill head to be dug up from above, increasing time and costs.

The drill head of the AXIS can retract, allowing the contractor to do a pilot line and inspect the ground.

Considering alternatives

While factors such as the right microtunnelling equipment and dedication to finding a solution to a difficult project go a long way in successfully completing high risk jobs deemed impossible, sometimes microtunnelling is not the best option for the task at hand.

Mr Harrison says when this is the case, it is the duty of the contractor to let the project manager know.

“We do our best to try and speak to contractors or an engineer who’s designing a project about site-specific issues about what we can offer,” he says.

“We’re also happy to let them know that maybe what we’re offering isn’t the best solution on their job.”

Trenchless technology comprises a broad category of equipment and solutions and within the sector, any trenchless professional can discuss variations in technology that all present varying strengths and limitations. Edge Underground understands using the wrong tool in an application can result in a disappointing outcome, both financially and structurally.

“So wherever we can get more industry professionals assisting to get designs right, relative to the desired outcome, I think we help our industry grow, because people that we’re working with gain confidence that they’re going to prescribe something that will be successful,” says Mr Harrison.

“I think everyone in the industry has the burden to assist that process, and help clients come to some sort of a great outcome from our advice, from what we’re putting in.”

This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Edge Underground website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

GM the go-to in WA

With 40 years of experience in the industry, the company has established itself as one of Western Australia’s most knowledgeable underground infrastructure companies.

GM Microtunnelling is part of WA’s history in the trenchless industry, with General Manager Gary Miller’s father Jim responsible for purchasing the first horizontal boring machine in the state. Gary and Jim recognised the increasing demand for this brand of underground construction and quickly established a name for themselves by winning contracts for various vital water and gas works.

The company adapted and progressed as the technology continued to improve through the decades and, although Jim eventually retired, GM continues as a family business today with Gary’s son and grandson both a part of the team.

Comprehensive knowledge

As both a primary or subcontractor, GM has installed pipelines beneath buildings, highways, railroads, runaways, rivers and environmentally sensitive areas. The company is capable of tunnelling through hard rock up to 660 m OD as well as cobbles, boulders, gravel, clay, sand and silts up to 800 mm OD, with its trenchless methods particularly suited to gravity sewer, water and drainage pipelines.

GM often works together with project engineers to provide planning and technical advice on a project and is able to set itself ahead of the pack thanks to its extensive knowledge of ground conditions throughout WA. Along with its local knowledge, the company has expert proficiency in the operation of a large variety of tunnelling machines including the Grundomat range and Essig air tools, along with auger, ramming, pipe bursting, pilot and slurry microtunnel boring machines (MTBMs).

With four complete systems in its fleet, GM can currently tunnel from 150 to 800 mm pipe to line and grade using polyvinyl chloride, concrete, vitrified clay, glass reinforced plastic and steel pipes. The company has its fingerprints over a large range of significant infrastructure projects in WA and is continuing to stay busy while the trenchless method of construction gains a greater standing as the approach of choice for many asset owners.

Some of GM’s works include the completed installation of a gravity sewer in Wungong Reach with a DN 650 Hobas pipe after a 1,200 m bore at a depth of 6.5 m. At Heron Park in Harrisdale, GM completed a 450 m bore at a depth of 9 m for a gravity sewer using DN 600 steel casing, while the company was able to bore 300 m at a depth of 5.5 m for a gravity sewer in Parkland Heights, Baldivis.

GM is a fully accredited contractor operating in line with integrated management system standards ISO9001 2015, ISO14001:2015, ISO45001:2018 and is an approved Tier 3 Water Corporation supplier.

Though it has already acquired a vast wealth of industry knowledge and experience, the company intends to lead the trenchless technology industry through its consistent embrace of new methods and innovative ideas. GM is regularly participating in and encouraging the training of new personnel in the industry and places the upmost importance on its quality of service.

This article was featured in the September 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the GM Microtunnelling website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

Diona secures QLD project

The project will connect into a new sewerage pump station (SPS266) currently being constructed by Diona under a joint funding agreement between Urban Utilities and Brisbane City Council.

The package of works comprises constructing a trunk gravity sewer main via a 250 m long by 12.5 m deep microtunnel from the existing SPS to SPS266, as well as a new sewer rising main to the Victoria Bridge abutment.

Diona Queensland State Manager Richard Willis said being involved in the early works for the city-shaping project is a fantastic opportunity that highlights the company’s continued success in delivering complex projects in challenging urban environments.

“Diona is working collaboratively with Council’s Brisbane Metro project team to ensure regular and timely communication with stakeholders and the community impacted by these works,” said Mr Willis.

“Due to the inner-city location on Grey Street in South Brisbane, there are a number of considerations and highly impacted stakeholders in the area.

“Controlling noise and vibration, along with traffic management, will be essential in ensuring minimal impact to businesses and community members during the construction period.”

For more information visit the Diona website.

If you have news you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

View the latest trenchless technology tenders

View the latest trenchless technology tenders

WRH copper pipe replacement main works
Issued by:
Capital and Coast District Health Board
Closing date:
5 August 2020
Location:
New Zealand
Description:
This WRH Copper Pipe Replacement Main Works project involves works pipes and valves as well as fittings and pipeline construction.

Newman Wastewater Treatment Plant Upgrade
Issued by: East Pilbara Shire Council
Closing date: 11 August 2020 
Location: Western Australia 
Description: The Shire of East Pilbara is seeking tenders from suitably qualified and experienced consultants to provide consultancy, preliminary design and superintendent services.

Construction of bore(s) – Dunsborough Non-Potable Water Project
Issued by:
Busselton City Council
Closing date:
28 August 2020
Location:
Western Australia
Description:
The City of Busselton is inviting tenders for to engage an adequately skilled and experienced contractor to: (a) construct, test and equip exploration, production and/or monitoring bore(s) on Mewitt Road, Quindalup as part of the City’s Dunsborough Non-Potable Water Network Project; (b) comply with DWER requirements in relation to a Hydrogeological Assessment Report for these bores (as specified in the Drilling Licence); and (c) if required, provide the city with a report on the beneficial use (availability, volume, quality and sustainability) of groundwater available for extraction from this bore(s).

Glenkenich Water Treatment Plant Upgrade
Issued b
y:
Clutha District Council
Closing date:
26 August 2020
Location:
New Zealand
Description
: Tenders are invited from suitably qualified and experienced tenderers to undertake water and sewage treatment plant construction for the Glenkenich Water Treatment Plant Upgrade.

Beechworth sewer trunk main and pump station
Issued by:
North East Water
Closing date:
31 August 2020
Location:
Victoria
Description: North East Water is seeking suitably qualified and capable contractors to act in the capacity of principal contractor to detail the final design and construct a sewage pump station and transfer main in the township of Beechworth, Victoria. The project context is diverse and challenging, requiring construction in undulating terrain and constricted spaces, microtunnelling within the ‘unrippable’ Mt Pilot granite and excavation and boring in Parks Victoria land and residential streets with heritage sensitivities.

Construction of Melton to Bacchus Marsh (M2BM) Interconnector Pipeline
Issued by: Western Water
Closing date: 10 September 2020
Location: Victoria
Description: Western Water is seeking tenders for the construction of the Melton to Bacchus Marsh (M2BM) Interconnector pipeline. The work involves: installation and commissioning of approximately 12 km of 600 mm diameter RRJ GRP pipe and associated fixtures; trenchless crossing of the Werribee River including design and installation of associated structures; and interaction with various landowners for construction within easements on private property/farms.

Each fortnightly edition of the Trenchless Australasia e-newsletter includes a list of tenders relevant to no-dig contractors, suppliers and manufacturers.

The information is provided by Australian Tenders, which is renowned for being an Australia-wide locally owned and operated tender notification service.

Australian Tenders is also offering readers of Trenchless Australasia an extra three months on their subscription plans.

Email support@australiantenders.com.au for more information.

For more tender information visit the Australian Tenders website.

If you have a tender you would like featured in Trenchless Australasia contact Assistant Editor Sophie Venz at svenz@gs-press.com.au

TBM travels to Australia

At 205 m long and 11 m in diameter, the TBM is considered large by global standards and has been designed specifically to tunnel on an incline.

In a social media post, Snowy Hydro Limited has shared images of the TBM’s construction, thanking Herrenknecht AG for the kit.

Image courtesy of Snowy Hydro Limited.

The completion of the TBM marks another milestone between Snowy Hydro Limited and its principal contractor Future Generation Joint Venture, comprising Webuild and Clough.

For more information visit the Snowy Hydro Limited website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

WATCH: TBM reaches milestone in Melbourne

The project’s tunnel boring machine (TBM) – supplied by Rob Carr – has just completed its 550 m journey from the 23 m deep launch shaft on Lonsdale Street to conclude at the Elizabeth Street shaft.

The Rob Carr and CWW project team will now continue work onsite and commence preparations to launch the TMB from the same launch shaft.

Once launched, the TBM will head 350 m back towards the Spencer Street reception shaft located in the opposite direction.

For more information visit the Rob Carr website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Lonsdale sewer progresses below quiet CBD

The Lonsdale Street Sewer Upgrade is the second stage of a four-stage strategy to install a secondary 900 m long sewer line under Lonsdale Street. Rob Carr was appointed by Melbourne utility City West Water (CWW) in June 2019, and – in association with design partner SMEC – has been diligently working to deliver the DN 1400 glassfibre reinforced plastic (GRP) sewer line in the heart of the city.

Rob Carr successfully launched the microtunnel boring machine (MTBM) from its 23 m deep launch shaft on William Street in February 2020 after completing weeks of excavation activities. The tunnel will be completed in two shots of 550 m and 350 m respectively, with a 1,500 mm outside diameter GRP to be used.

Monitoring the location of the MTBM.

As of late April 2020, Rob Carr had tunnelled approximately 350 m through the first drive, with operations underway 24 hours a day, six days per week. Rob Carr Construction Manager Andrew Scarr says as with any tunnelling job there have been challenges, but the team was continually able to work its way through.

“We were below the water table at all points, but the permeability of the ground is quite low, so we turn on the pump twice per day at the launch shaft to keep the water down,” he says.

“At about 300 m we came into some river rock, or river pebbles – like an old riverbed. It had high inflow so that was a challenge for the operators.”

A bird’s-eye view of the sewer with 300 m installed.

Tunnelling during a pandemic

The shadow of the COVID-19 has hung over much of 2020 so far, with many operations hardly continuing in a fashion that could be described as ‘business as usual’. However, the work goes on for Rob Carr on Lonsdale Street, albeit without the hustle and bustle usually expected in a dense urban area such as Melbourne’s CBD.

Mr Scarr says after the solving some minor logistical issues with workers coming in from interstate, the surrounding noise, or lack thereof, in the project’s location was the biggest difference from when works began.

“It’s significantly quieter, like a ghost town,” he says. “Often it’s more like a quiet Saturday afternoon than a weekday with how little people and traffic is around.”

Rob Carr and CWW have been adhering to all coronavirus prevention guidelines onsite, including having ample supplies of hand sanitiser, putting up relevant signage and practicing social distancing. Through it all, Mr Scarr says the team’s performance has been first rate.

“Everyone is working well together and CWW is always on hand to help where they can, particularly with the challenges presented by COVID-19.

“We are still on track to complete the project in 2020.”

This article was featured in the June 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Rob Carr website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Digital edition now live!

The most recent quarterly update for the trenchless technology industry in Australasia is now available to view online.

This edition showcases how Trenchless Australasia is staying current alongside industry developments, with a modern look and a digitally interactive edition for the ease of readers.

The June edition includes:

  • An article on New South Wales’ extended construction hours and the benefits to the no-dig sector.
  • A positive news feature, highlighting local trenchless businesses and contractors who are staying busy during COVID-19.
  • An overview of the City of Logan’s longest horizontal directional drilling bore.
  • And much more!

We love to see people enjoying the magazine from the comfort of their own homes; please feel free to send through images of yourself reading the June edition, which we will feature online.

Click here to view the digital edition of magazine; if you share it online, don’t forget to tag our Twitter, Facebook or LinkedIn social media handles so we can like and share your post!

You can also download a PDF of this and past editions of the magazine from the Trenchless Australasia magazines page.

If you have news you would like featured in Trenchless Australasia please contact Journalist Sophie Venz at svenz@gs-press.com.au

D.J. Mac Cormick hits the right notes in Townsville

The Haughton Pipeline Duplication Project (HPDP) involved the duplication of a 36.5 km pipeline from the Haughton Pump Station to the Ross River Dam in order to provide a bulk raw water supply the area.

The alignment of the DN1800 GRP pipeline included crossing beneath state-controlled Flinders Highway and a Queensland Rail (QR) rail corridor, which required D.J. Mac Cormick Contractors to install a 120 m long 2.5 m outside diameter enveloper pipe using the trenchless pipejacking method.

Before works began, several authority approvals and permits were acquired, including a QR Wayleave, compliance the QR’s civil engineering requirements and Department of Transport and Main Roads permits.

Detailed temporary design was undertaken for launch shaft shoring, thrust block, the concrete pad and entrance wall, as well as the receival shaft design for microtunnel boring machine (TBM) removal, while the jacking system employed was capable of up to a 850 t safe jacking load.

A detailed design was completed for the launch pit.

A Herrenknecht tunnelling system was selected to undertake the project with a mixed cutting wheel chosen based on the expected ground conditions that ranged from stiff sand and clay to granodiorite rock.

The subsequent 120 m drive length was completed in 11 days at a depth of approximately 2.5–3 m below the surface, followed by the grouting of annulus outside of the pipe.

Spoil removal monitoring works were undertaken on each pipe as the construction advanced to ensure no excessive excavation occurred and the 2.1 m internal diameter concrete jacking pipes were supplied by Humes.

An air pressure test was conducted at the conclusion of the installation to certify the line to proper sewer standards and a detailed survey of the pipe post-construction found no defects.

This article was featured in the June 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the D.J. Mac Cormick website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Edge Underground evolves with the industry

Although microtunnelling is still a relatively new technology, it is continuously involving as its methods are improved, making it a more reliable means of installing pipelines on time and in budget.

However, to ensure the technology continues to evolve, Edge Underground Managing Director Stuart Harrison says contractors and subcontractors need to be open to taking a flexible approach on projects to produce the best possible outcome.

A modern technology

“Developed in Japan in the 1970s, microtunnelling is still considered a new technology that is continuing to evolve as machinery and techniques continue to be improved,” says Mr Harrison.

“This means it is new enough for engineers to be wary of it—especially if they have never used it before—but also old enough for current practices and procedures to be established.

“I see our industry as in its infancy—even though it’s been around for almost 50 years—because when it was first developed, the methodology wasn’t consistent and only got it right some of the time.

“But we’ve evolved a lot since then, and little by little the methodology has been improved to the capabilities of some of the best microtunnelling machines on the market today which can consistently achieve accuracies of ±10 mm.”

Mr Harrison says the industry is still evolving and he believes the growth over the next ten years will be big and exciting.

An evolving industry

Mr Harrison says the evolution of the industry in the coming years will rely on a host of different factors including products and design, not solely on the improvement of equipment or work practices.

“It’s about pulling it all together to make a package that is truly competitive, and a true alternative to open cut,” he says.

“Before we even start a job, we’re trying to help companies eliminate risk. At the end of the day, when you get risk wrong, that’s when budgets get destroyed. So, whenever you can find a situation where you can reduce risk, you get a more accurate way of knowing what the final cost will be.

“That is a critical part of our industry moving forward; whenever we get the opportunity to create a methodology that reduces risk, we can create outcomes that everyone’s looking for.”

Working with a flexible contractor that is open to new ideas helped Edge Underground find success at this Melbourne-based project.

Edge Underground offers a piece of the puzzle

Edge Underground understands it’s not always easy to get engineers and contractors unfamiliar with microtunnelling on board with the method, but finding ways to improve and reduce jobsite risk requires everyone to be open to a flexible work approach.

“We’re a piece of a puzzle on a job site, and we offer a very specialised service to deliver a pipeline from A to B accurately in a very wide range of ground conditions,” says Mr Harrison.

“As a company, Edge Underground will take on even the hardest jobs that no other microtunnelling contractor is willing to touch, and in doing this we will look for the best and most economical way of completing the project in the provided time frame and budget.

“Sometimes this means finding an unconventional way of doing things, especially when there are challenging conditions, but everyone needs to be open to giving it a go.”

An innovative solution

This flexible approach has allowed Edge Underground to complete projects in difficult conditions and challenging time frames when other subcontractors may not.

“In one instance, we completed a 300 m PVC sewer pipeline installation in Maribyrnong in Melbourne’s inner west, which had to be completed in a tight access area near existing infrastructure, but also needed to be completed in a short time frame,” says Mr Harrison.

“There was such as tight time frame to complete the project that it would’ve been difficult to put shoring into place without taking longer than specified.

“When this happens, working with a flexible contractor that is open to new ideas is a great benefit to finding a solution to get the job done.

“We worked on this project with Eden Drainage, and working together we were able to come up with a solution; we essentially shotcreted the tight access shafts, allowing us to complete the job in the specified time.”

Mr Harrison says that having everyone on board to come up with a flexible and innovative approach to the job – rather than simply going with the conventional, preconceived idea – is what ensured the successful outcome.

This article was featured in the June 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Edge Underground website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Vermeer sets a rock-solid standard for HDD

HTD understands that having access to the right horizontal directional drilling (HDD) equipment is crucial to achieving successful outcomes on its projects. With a specialty in trenchless techniques for the installation of conduits and pipelines beneath paths, driveways, roads, rails, airport runways and congested or environmentally sensitive areas, HTD says it ensures this success by using Vermeer’s HDD machinery.

Extensive services providing calls for an extensive fleet

HTD’s services include the installation of utilities – such as gas mains, water mains, recycled mains, rising sewer mains and stormwater – as well as electrical and communications conduits, and HTD Australia Project Engineer Andrew Smith saying its expertise is in the delivery of technically challenging projects that require precise drilling.

“Our in-house team ensures all works are scoped, coordinated and planned professionally through site meetings and walkovers, with the capability to provide engineered bore designs, construction methodologies and associated project documentation,” says Mr Smith.

“HTD’s directional drilling capabilities include the installation of single, multiple and on-grade utility services for projects ranging from smaller pathways to significant under-boring crossings up to 800 mm in diameter, in all ground conditions.”

HTD Australia prides itself on maintaining its plant and equipment to ensure the safe and efficient delivery of its projects, with numerous Vermeer machines included in its fleet.

Mr Smith says HTD has purchased four horizontal directional drills from Vermeer – a D6x6, D20x22 Series II, D36x50 Series II and a D36x50DR Series II – and considers several Vermeer vacuum excavator trucks, locators and mud pumps as an essential part of their fleet.

“Vermeer equipment offers several benefits over any alternatives considered, including the reliability and engineering of the products, and the assurance that if the plant is properly maintained it will operate as intended,” says Mr Smith.

HTD specialises in vacuum excavation and under road drilling.

A partner in pipeline projects

Mr Smith say HTD used its Vermeer D36x50 Series II HDD rig, built to perform a wide range of medium diameter, moderate-to-long distance utility installations, on a recent project.

The Queensland project involved the collective installation of six electrical and communications conduits, ranging from 110-140 mm, for 70 m to upgrade the utility services for the development and operation of the Gold Coast Sporting Precinct.

“The delivery of this project required HTD to drill through siltstone rock, design bore profiles detailing the depth and chainage of the drill, and meet stringent technical and safety specifications,” says Mr Smith.

Vermeer says its Series II line has now been superseded by the latest, next-generation S3 range, which features more power, increased speed, versatility and precise control.

Additionally, the D40x55 S3 horizontal directional drill, which features 40,000 lb (177.9 kN) of thrust/pullback and 5500 ft-lb (7457 Nm) of rotational torque, is a 10 per cent increase in thrust and rotation on its predecessor and will help maximise productivity.

The D40x55 S3 also features a carriage speed of 188 fpm (57.3 m/min) – seven per cent faster than the D36x50 Series II – which will help contractors install more linear feet per day.

With a 104 dB(A) guaranteed sound power level and an operator ear rating of 82.9 dB(A) [in-cab rating of 75.7 dB(A)], the D40x55 S3 is also significantly quieter – contributing to a quieter working environment with less community disturbance and easier communication among crews.

Mr Smith says by using the smaller footprint of the Vermeer D20x22 Series II HDD on a project for Brisbane City Council, HTD could minimise its construction footprint, protect existing gardens and historical sensitivities and limit disruption to pedestrian traffic.

“This project involved the construction of 17 bores, installing 700 m of 180 mm irrigation and 90 mm water main collectively to upgrade the Brisbane City Botanical Garden’s water infrastructure,” says Mr Smith.

A true multi-use machine with the ability to work in varying soil conditions including solid rock, the D20x22 Series II has 20,000 lb (89kN) of thrust/pullback, which provides the performance needed to complete a wide range of bores.

A Queensland-based company, HTD has been using its Vermeer machinery across the state.

The strength of relationships

Mr Smith says having a strong relationship with suppliers such as Vermeer is equally as important to the success of the business as its clients are.

“HTD Australia has had a strong relationship with Vermeer for the past 15 years, visiting the US factory in Pella, Iowa, multiple times,” says Mr Smith.

“This has allowed HTD to gain a better understanding of how to run and maintain our HDD equipment and plant, and appreciation for the work that goes into Vermeer machines.

“Having reliable suppliers that consistently produce high-quality products and offer a supportive after-sales service allows HTD to maintain the high quality and effective service our clients expect.”

This article was featured in the June 2020 edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet or mobile device, click here.

For more information visit the Vermeer website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

View the latest trenchless technology tenders

View the latest trenchless technology tenders

Iron Bridge Magnetite Project – concentrate and return water pipelines
Issued by:
IB Operations Pty Ltd
Closing date:
14 April 2020
Location:
Western Australia
Description
: The works for this package includes but is not limited to the following:provision of all resources; supervision; labour; transportation; materials; construction plant and equipment; communications and other items necessary for the logistics; detailed earthworks and concrete, civil works; mechanical works; electrical and instrumentation; pipeline installation and commissioning. Trenchless crossings must be completed, including micro-tunnelling rail crossing and road crossing, by other approved methods such as horizontal directional drilling (HDD), auger boring and thrust boring.  

Construction of STW’s approximately 1,400m of 225mm PVC PN12 rising sewer main
Issued by:
Warren Shire Council
Closing date:
17 April 2020
Location:
New South Wales
Description:
Warren Shire Council is seeking expressions of interest for businesses with civil construction and pipe laying skills to join a panel of providers and companies, for the construction of an approximately 1,400 m of 225 mm PVC PN12. The pipeline is to be constructed in two parts. Companies will need to demonstrate they have the experience and ability to trench and lay pipes with bedding and compacted cover.

Construction of Solomon Dam Raw Water Pipeline
Issued by:
Department of Local Government & Racing and Multicultural Affairs
Closing date:
17 April 2020
Location:
Queensland
Description
: The Queensland Government is seeking proposals from suitably qualified contactors for the supply, delivery, construction, installation, testing and commissioning of the Solomon Dam Raw Water Pipeline Upgrade. The scope of works for the project includes, but is not limited to: supply, delivery, construction, installation, testing and commissioning of approximately 420 m of DN300 DICL PN20 raw water pipeline connecting Solomon Dam to the Water Treatment Plant Inlet Shed, including new valves and fittings installation in the existing scour pit.

Mount Barker Regional Sports Hub and Surrounds Sewer Scheme
Issued by:
Mount Barker District Council
Closing date:
20 April 2020
Location:
South Australia
Description: Mount Barker District Council invites tenders from tenderers for the construction of Mount Barker Regional Sports Hub and Surrounds Sewer Scheme. The pipelines traverse a Greenfields site, with the exception of a road crossing for the connection into the council’s existing wastewater system. The pipe laying may be undertaken by either open excavation or directional boring. Bored pipeline shall be HDPE PN12.5.

Awaiti Place and Ohauiti Reserve stormwater upgrades early contractor involvement
Issued by:
Tauranga City Council
Closing date:
21 April 2020
Location:
New Zealand
Description: Tauranga City Council invites registrations of interest for this contract comprising the construction of an attenuation facility in the Ohauiti Stormwater Reserve and upgrade and construction of a pipeline from Awaiti Pond to Poike Rd.

Echuca, McKenzie Road drainage
Issued by: Campaspe Shire Council
Closing date:
28 April 2020 
Location:
Victoria
Description:
Campaspe Shire Council (CSC) is seeking the services of a suitably qualified and experienced contractor to conduct drainage works linking drainage in the areas of Anderson Rd, the Echuca Aerodrome, McKenzie Rd and a property east of McKenzie Rd. The works will include drainage works, undertrack boring works in the vicinity of Anderson Rd, Echuca (VicTrack) and roadworks.

Each fortnightly edition of the Trenchless Australasia e-newsletter includes a list of tenders relevant to no-dig contractors, suppliers and manufacturers.

The information is provided by Australian Tenders, which is renowned for being an Australia-wide locally owned and operated tender notification service.

Australian Tenders is also offering readers of Trenchless Australasia an extra three months on their subscription plans.

Email support@australiantenders.com.au for more information.

For more tender information visit the Australian Tenders website.

If you have a tender you would like featured in Trenchless Australasia contact Head of Production Chloe Jenkins at cjenkins@gs-press.com.au

New technologies raise the bar

These modernisations include high stress crack resistant polyethylene pipe (HSCR PE), the Magnetics Mag8 Walkover Tracking System and use of Time of Flight Diffraction Ultrasonic Testing technology, in addition to the trenchless method of horizontal directional drilling (HDD).

The Logan City Council says trenchless installation was chosen as the most practical solution considering it avoided the need for a major diversion and longer pipeline route. HDD was specifically used for the pressure main installation as the profile can be curved, avoiding the need for deep entry and exit pits – as opposed to alternative trenchless methods that were considered such as microtunnelling.

Project overview

Logan Water Infrastructure Alliance Manager Mark Vaughan and Downer Project Manager Graeme Nicholson said the project was completed in only eight weeks, including the time for setting up and demobilising the equipment.

“After setting up the drill rig and associated tanks and equipment for processing and recycling the drilling mud, a mud return line – 160 mm diameter – was strung out over land and suspended across the river,” said Mr Nicholson.

This process allows the drilling mud to be pumped back over the river for cleaning and recycling, which is a part of the drilling process. Following this, drilling commenced with installation of the pilot bore of 250 mm for the full length of the drill.

The drill head was steered according to a pre-designed drill profile up to 24 m beneath the river and the pilot bore was reamed up to size required for the product pipe in two stages of 450 mm and 900 mm. Simultaneously, the product pipe was welded together in a continuous pipe string of 480 m and made ready for pulling into place.

HDD technologies

HSCR PE is a recent innovation in materials technology, which has been specified in other HDD projects by the Logan City Council recently. Since trenchless technology applications can increase the risk of pipes being damaged during installation and subsequent cracks in the pipe propagating over time, HSCR PE – supplied by Iplex – was used as it contains a resin that reduces this tendency.

Additionally, Mr Nicholson says the Magnetics Mag8 Walkover Tracking System was first used in Australia on a wastewater pipeline project also in Logan, which is currently under construction. The Logan River HDD, however, is the first project to be completed using this technology.

The tracking system was used to monitor the location of the drilling head and ensure the drill followed the correct alignment in combination with a maxi drill rig. The tracking system can track drilling up to 90 m deep, which is much deeper than competing systems that can usually only track to 18 m.

Time of Flight Diffraction Ultrasonic Testing technology

The new technology was used to test every weld on the pipe, which added confidence in the integrity of each of the pipe welds. Sound waves were transmitted through the weld to reflect signals back to the operator that were then analysed to determine whether there are any hidden faults.

Destructive testing of selected welds will only indicate deficiencies in the pipe welding method and not specific defects in each in situ weld – as they must be destroyed to be tested in such a way – so it was not considered sufficient in isolation. Ultrasonic testing, however, is one of the only non-destructive test methods that can identify invisible defects.

Aerial shot of the HDD project site on the banks of Logan River.

Comprehensive testing regime

“A number of testing and quality assurance measures were implemented ‘over and above’ industry normal practice for horizontal directional drilling pipe installation to ‘raise the bar’ and provide added assurance against future pipe failure given the proximity of the sewer pipe to the Logan River,” says Mr Vaughan.

This included the ultrasonic testing of every pipe weld to ensure any defects or imperfections in the weld were identified, with the implementation of a ‘zero defect’ criteria to ensure rejection of any defects in the weld whatsoever. Additionally, a pre-installation pressure test on the welded pipe string was carried out where typically only a post-installation pressure test is undertaken.

Mr Vaughan says that an additional section of the pipe of approximately 10 m was pulled through the underground drill to inspect the pipe and confirm any damage caused to the pipe surface during the pulling process was within acceptable limits.

“As well as the [aforementioned], it’s fairly standard practice to carry out ‘destructive testing’ of pipe welds,” says Mr Vaughan.

“It was ensured a pilot test weld was sent to the lab and pulled apart to prove that the welding methodology and equipment was sound before pipe welding could start on the permanent works. A sample of further welds were also destructively tested.”

Additional consultations

Mr Vaughan and Mr Nicholson said a lot of effort went in to preparing and implementing the regimen for the high standard of quality assurance, in which documents were prepared by the HDD contractor in line with this specification. Third party consultants were also engaged, including Le Hunt Consulting Engineers and Trenchless Adviser.

Le Hunt Consulting Engineers was able to recommend procedures and testing that would ensure a high-quality outcome and additionally review the contractor’s quality assurance documents prior to approval of the works commencing.

Meanwhile, Trenchless Adviser was engaged to oversee the contractor’s work in the field and ensure the suitability of methods and equipment. Additionally, drill logs were reviewed and both drilling pressures and mud return quantities were monitored to ensure the risk of frac out was mitigated.

Project success

The Logan City Council’s Flagstone to Cedar Grove Wastewater Treatment Plant project was completed on time and under budget with no environmental incidents. The council attributes this mainly due to the use of efficient drilling methods and completing pipe reaming in two passes – as it reduced the risk of ‘frac outs’ by minimising drilling timeframes.

By choosing, managing and executing HDD to its full potential, the project achieved a lowest impact construction method for both the community and the environmentally sensitive area of the Logan River waterways.

For more information visit the Logan City Council website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Rob Carr digs deep in Melbourne

The second instalment of a four-stage strategy to install a secondary 900 m long DN 1400 glassfibre reinforced plastic (GRP) sewer line under Lonsdale Street in the heart of Melbourne’s CBD, the Lonsdale Street Sewer Upgrade is progressing on schedule through the work of expert trenchless contractor Rob Carr and major Melbourne water utility City West Water (CWW).

Melbourne’s sewer network is more than a century old and a range of sewer works have been tabled by the Victorian State Government in order to prevent the prospect of an outdated and inefficient system.

Rob Carr was appointed by CWW in June 2019 and, with its design partner SMEC and client CWW, liaised with all relevant stakeholders to ensure the project commenced on schedule and in an orderly fashion.

Launch time

After weeks of excavation activities, Rob Carr completed the 23 m deep, 6 m inside diameter (ID) launch shaft on time in late February 2020, with all jacks set and the microtunnel boring machine (MTBM) lowered in at the site on Lonsdale Street between King and William streets.

Rob Carr Construction Manager Andrew Scarr says, at the time of launch, the team was continuing to work on the retrieval shaft near the corner of Lonsdale and Elizabeth streets.

“The piling has been completed and we’re excavating at the moment. We’re about 4 m down and we have to divert a sewer, then we’ll be dig down to approximately a 9 m depth for the retrieval of the MTBM,” says Mr Scarr.

The 900 m tunnel will be completed in two shots of 550 m and 350 m respectively, with 1,500 mm outside diameter GRP pipe to be used. Mr Scarr says Rob Carr anticipated the initial 550 m drive would be completed in approximately seven weeks.

“We currently have around 15 staff working on site, which will ramp up to just over 20 once we move to working double shifts,” he says.

“During the drilling of the mainline we also have to complete a short 20 m drive from the Elizabeth Street retrieval shaft into an existing manhole before we retrieve the MTBM. We then we have to turn the machine around and drill the remaining 350 m down to Spencer Street.”

With works going ahead as planned and on schedule, Rob Carr anticipates works are on track to be completed by late 2020.

For more information visit the Rob Carr website.

If you have news you would like featured in Trenchless Australasia contact Journalist Sophie Venz at svenz@gs-press.com.au

Melbourne sewer upgrades progressing

At the conclusion of 2019, works to install a new sewer pipeline on Lonsdale Street had progressed through to Elizabeth Street, with westbound traffic on Lonsdale from Elizabeth Street to now be reduced to one lane until May this year as operations continue.

The microtunnel boring machine (MTBM) will be launched from William Street in February and is anticipated to arrive near Elizabeth Street in May, after which it will return to the launch shaft to tunnel westward to Spencer Street.

Rob Carr is delivering the project on behalf of City West Water (CWW), with the sewer upgrade to connect with the recently completed Spencer Street Sewer Upgrade upon completion.

CWW General Manager Infrastructure and Delivery Amanda Smith said traffic in the area would be impacted for some time.

“We’ve been working closely with the City of Melbourne and public transport operators to help them maintain normal timetables, however nearby infrastructure and high-rise construction may also cause short delays,” she said.

The upgrades form part of a four-stage AU$80 million capital improvement program to maintain service reliability for Melbourne’s growing population.

For more information visit the CWW website.

If you have a project you would like featured in Trenchless Australasia contact Head of Production Chloe Jenkins at cjenkins@gs-press.com.au

McConnell Dowell awarded new Auckland project

Auckland Council’s Healthy Waters department awarded McConnell Dowell the St Marys Bay and Masefield Beach Water Quality Improvement Project – one of the first of several projects that will reduce the number of overflows in Auckland from 100 per year on average to 20.

The project will include the installation of nearly 2 km of new pipeline, with approximately 1,120 m of the alignment to be tunnelled using a new Herrenknecht microtunnel boring machine.

The 1.8 m ID reinforced concrete pipes will be jacked into place, while the final 25 per cent of the pipeline will be constructed from high-density polyethylene and will form the outfall, which will be joined offsite and lowered into place on the seabed in a controlled sink.

Only 25 per cent of the pipelines will be installed using traditional dig and lay methods.

McConnell Dowell Managing Director New Zealand and the Pacific Islands Fraser Wyllie said the use of trenchless technology will reduce disruption to both the land and nearby stakeholders.

“McConnell Dowell has considerable expertise in this area having constructed all of the largest marine outfalls in New Zealand,” he said.

“We are proud to be able to help improve water quality in our harbours and beaches and help provide a better life to communities.”

Construction is set to commence in January next year and is tabled for completion in late 2021.

For more information visit the McConnell Dowell website.

If you have news you would like featured in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au

Metro Tunnel amps up work

Since late October the Metro Tunnel’s second tunnel boring machine (TBM) Meg been tunnelling and progressed approximately 50 m towards the tunnel entrance in Kensington, installing more than 20 rings.

The project’s first TBM, Joan, had already travelled more than 250 m west from North Melbourne and installed more than 140 rings to line the new tunnel.

Both Joan and Meg are expected to arrive in Kensington – the western entrance to the Metro Tunnel – in early 2020 before being returned to the North Melbourne site and relaunched towards Parkville for the second leg of their journey.

Early next year, two more TBMs will be assembled at the Anzac Station site on St Kilda Road, ready to start boring towards the eastern entrance at South Yarra.

Victoria Minister for Transport Infrastructure Jacinta Allan is excited by the progress so far.

“I’m delighted to see the progress being made by these huge tunnel boring machines,” said Ms Allan.

“It’s an early glimpse of what the Metro Tunnel will look like.”

In January, the excavation of the Metro Tunnel’s final section at South Yarra will begin as crews begin shifting the existing train tracks to make room for the new track.

Once finalised, the Metro Tunnel will provide space on the rail network for over half a million extra trips a week to and from the suburbs during peak periods, slashing travel times by up to 50 minutes a day.

However, during the works, sections of the Cranbourne, Pakenham, Frankston and Sandringham lines will be closed.

Victorian Premier Daniel Andrews said these vital upgrades and biggest transport projects in history are essential to ensuring the city and state don’t grind to a halt.

“We know it will be disruptive but with less people on our roads and rail, it’s the right time to get this work done,” said Mr Andrews.

For more information visit the Metro Tunnel website.

If you have news you would like featured in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au

View the latest trenchless technology tenders

View the latest trenchless technology tenders

Trenchless sewer repairs
Issued by:
South East Water Corporation
Closing date: 5 December 2019
Location: Victoria
Description: Trenchless repair services and activities include, but are not limited to:

  • programmed spot repair of a failed or failing sewer asset
  • installation of approved South East Water patches, quick locks, top hats and lateral connection liners
  • flow management from task award to task completion – appropriate bypass pumping and diversion and flow control during patching operations is to be carried out including flow control of the services specifications and flow management plans to be approved by South East Water prior to commencement of works
  • CCTV inspection of assets both before and after repair
  • cleaning of the sewer asset pre commencement of repair
  • potential emergency call-out for after-hours repair
  • rehabilitation or sealing of property connection junctions.

Sydney Metro Tunnelling – engineering and construction specialist services
Issued by: Sydney Metro
Closing date: 9 December 2019
Location: New South Wales
Description: Sydney Metro is seeking to engage a service provider responsible for providing a tunnelling – engineering and construction specialist services for relevant work streams. Expected mobilisation is March 2020 for a period of two years on a part-time basis of three days per week.

Elliott Heads sewer pipeline
Issued by:
Bundaberg Regional Council
Closing date:
10 December 2019
Location:
Queensland
Description:
The customer requires a contractor to supply and installation of DN 150 sewer pressure main. The earthworks include, but are not limited to trench excavation, pipe installation, placement of embedment and trench backfill material, disposal of surplus material and acceptance testing requirements associated with the earthwork activities.

Sewer main renewals
Issued by:
Grampians Wimmera Mallee Water
Closing date: 12 December 2019
Location: Victoria
Description: GWMWater invites tender submissions for Sewer Main Renewals Program 2019–20. This contract includes two separable portions of works located throughout its operational region, with scope of works including relining of approximately 5,880 m of mains and relining of approximately 51 HCBs.

Supply and construction of sewer rising main 71
Issued by:
Port Macquarie Hastings Council
Closing date:
19 December 2019
Location:
New South Wales
Description:
Port Macquarie Hastings Council is seeking tender submissions from suitably experienced firms or persons for the provision of supply and installation of approximately 2 km of DN 375 ductile iron pipes (DICL) and polyethylene (PE) pipe from Greenmeadows to John Fraser Place Port Macquarie.

Each fortnightly edition of the Trenchless Australasia e-newsletter includes a list of tenders relevant to no-dig contractors, suppliers and manufacturers.

The information is provided by Australian Tenders, which is renowned for being an Australia-wide locally owned and operated tender notification service.

Australian Tenders is also offering readers of Trenchless Australasia an extra three months on their subscription plans. Email support@australiantenders.com.au for more information.

For more tender information visit the Australian Tenders website.

If you have a tender you would like promoted in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au

Mitigating the challenges of installing pipeline under railways

Changing ground conditions

Understanding the prevailing ground conditions is key to achieving a successful microtunnelling installation, as this will determine the tooling used and help the contractor plan.

“The more that the contractor knows about the ground conditions at and around the site, the less chance there is of unexpected complications occurring,” says Mr Harrison.

“This becomes even more important when microtunnelling under infrastructure such as railways because a sudden and unexpected change in ground conditions can cause a lot of problems. Imagine you’re microtunnelling under a railway and the ground changes or you come across an obstruction.

“The whole project has to stop, and in the worst case scenario – if you’re using a machine without a retractable head – you’ve potentially got a situation where the cutter head is stuck under the railway and needs to be dug out somehow, which is a difficult and costly job.”

According to Mr Harrison, the problem with ground conditions is it’s not uncommon for contractors and subcontractors to arrive on site and find that they are somewhat different to the geotechnical information provided for a particular job. This is because core samples and the geotechnical inspection are like searching for needles in a haystack; it’s not hard to miss spots where the ground changes.

“This is where having the right equipment will increase the chance of success on projects where a pipeline needs to be installed under railway,” he says.

Edge Underground set up on a microtunnelling construction site.

Saving the day with retractable equipment

Mr Harrison says to have the best chance of mitigating these problems and having a successful installation, you need to identify the difference in the geotechnical information versus what is actually there as early as possible.

“To be able to identify if the geotechnical information is wrong, you need a machine such as the Vermeer AXIS laser guided boring system, which has been designed to retract,” he says.

“Most microtunnelling machines can only move in a forward direction; however, the Vermeer AXIS can perform a pilot line through the ground and if any issues are encountered, it can retract, allowing the contractor to inspect the ground. Because the pilot line can be retracted, the contractor can effectively trial different drill heads during the pilot stage and assess which one will be the best for the prevailing ground conditions.

“Once the pilot is complete, the contractor can commence jacking the final product pipe with a far greater likelihood of success, as the ground conditions are now predominantly known.”

The other benefit of using a machine that has the ability to retract part-way through an installation is that no excavation is needed if there is a significant change in the ground.

“By being able to retract the drill head, contractors eliminate the need to excavate over the head in the situation of head failure or ground change,” says Mr Harrison.

“This feature ultimately saves time and money on what could become a difficult situation if the head becomes stuck directly under the railway.”

This article was featured in the June edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet, or mobile device, click here.

For more information visit the Edge Underground website.

If you have a project you would like featured in Trenchless Australasia contact Assistant Editor Chloe Jenkins at cjenkins@gs-press.com.au

MTBM heads for Melbourne renewal project

City West Water’s M205 Carlton Water Main Renewal Project is an essential upgrade to ensure safe and secure water supply for Carlton, its surrounding suburbs and the inner city.

This week, the MTBM is on its way to Elgin Street to continue the new main’s Stage 1 construction works, which commenced earlier in August, focusing on the Canning Street and Elgin Street intersection.

The scope of the project includes installing 2.3 km of new pipe along Canning Street, between Faraday Street and Park Street.

The current 140-year-old pipe runs under Nicholson Street and will be replaced and relocated, with the new main at Canning Street to almost double capacity to meet the growing population of the city.

City West Water has contracted Jaydo as its construction partner to deliver the M205 Renewal Project.

The project is anticipated to be completed in mid-2020.

For more information visit the City West Water website.

If you have a project news you would like featured in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au

Forrestfield-Airport Link hits new milestone

TMB Grace has now tunnelled more than 5.6 km and installed more than 3,300 rings, while TBM Sandy has tunnelled more than 4.8 km and 2,800 rings following relaunch after achieving breakthrough at Redcliffe Station in July.

At the Redcliffe location, temporary tunnel segments that helped guide the TBM into the station are being dismantled in preparation for platform and station works.

The next stage has now begun for the project following the completion of the Forrestfield to Redcliffe tunnelling, with tunnel fit-out beginning.

Almost a kilometre of the first section of the infill base slab has been constructed with an extra long drainage pipe and close to 500 m3 of concrete laid.

TMB Grace will now begin tunnelling underneath the Tonkin Highway road reserve in Ascot.

For more information visit the Forrestfield-Airport Link website.

If you have a project news you would like featured in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au

West Gate Tunnel diversion is complete

The West Gate Tunnel project has reached an important milestone, reaching completion of the North Yarra Main Sewer diversion.

After a year of work, the 600 m diversion construction has been finalised – an important first step toward creating the West Gate Tunnel itself.

Diverting the pipeline was a large task that required a microtunnel boring machine to dig the new pipe and break into the new sewer, as well as piling, changes to traffic and the excavation of over 9,000 m3 of dirt.

The aim was to build the diversion without interrupting to sewerage services during the works.

The existing North Yarra Main Sewer is 2,600 mm in diameter, more than 100 years old and is mostly made of bricks, running below the centre of Whitehall Street in Footscray and Yarraville and carrying 20 per cent of Melbourne’s sewerage.

With the diversion complete, Whitehall Street will be reopened for traffic in both directions.

Tunnelling of the West Gate Tunnel is set to commence this year, with the process expecting to take two years to complete with the ‘Vida’ and ‘Bella’ tunnel boring machines.

The West Gate Tunnel Project is a city-shaping project that will deliver a vital alternative to the West Gate Bridge.

For more information visit the West Gate Tunnel project website.

If you have a project you would like featured in Trenchless Australasia contact Managing Editor Chloe Jenkins at cjenkins@gs-press.com.au