The installation of underground utilities has the potential to cause major disruption to the community and surrounding environment depending on the method used. Microtunnelling offers an alternative solution to open cut methods for installing pipelines quickly and accurately while lowering the social costs.
Traditional open cut methods of pipeline installation require the length of the pipeline – which may include roads and footpaths – to be blocked off for a period of time to allow excavation, installation and restoration works to take place.
According to Stuart Harrison, Managing Director of Edge Underground, using a trenchless method such as microtunnelling instead of open cut methods has a number of benefits that limit the disruption caused by the construction work.
“Microtunnelling is a pit-launched technique with only an entry and exit pit required to be excavated for the installation,” says Harrison. “This allows installation through one small incision between the entry and exit pits, rather than having to tear the whole street open to do it.”
Limiting disruption to the community
The AXIS guided boring system is a modular microtunnelling machine that can be set up in a way that reduces the amount of space needed for the construction site, therefore reducing the amount of pedestrian pathways taken up and the need for road lane closures.
Additionally, this reduces the loss of parking spaces, which can lead to decreased parking meter revenue for the city and lower revenues from parking fines.
Another social cost of pipeline installations is the loss of trade. Construction zones can decrease accessibility to businesses due to congested traffic conditions, blocked parking spaces and barriers from the construction site itself.
Businesses can lose customers, who prefer to go to more convenient places, and those depending on deliveries may have problems with their supplies. Microtunnelling requires less excavation and less restoration afterwards, so project times are shortened, minimising the disruption to trade.
“While open-cut methods leave lengthy stretches of open trenches that need to be restored after construction, microtunnelling leaves minimal surface scarring and requires significantly less restoration of the landscape,” Harrison says.
Depending on the project requirements, destruction of road surfaces may be able to be designed out of the project altogether.
“Unlike traditional methods, the AXIS system extracts the ground being tunnelled through rather than displacing it. It is designed to cut and extract the ground as it proceeds, and in doing so has little to no influence on the ground directly surrounding the installation,” says Harrison
The AXIS system also uses a vacuum extraction method that provides continued support to the ground by using a pipe jack system approach. This ensures quantities of both incoming and outgoing materials are reduced, causing less disturbance to the environment and minimising the size of the work site.
A healthier and safer work site
Open excavations result in a significant amount of dust in their surroundings. Cleaning needs, and thus costs, increase while the quality of life for people living near the construction zone decreases. As excavation requirements are drastically minimised with microtunnelling, there is also less dust produced by the site.
Noise pollution is also a major by-product of construction sites. The use of heavy construction equipment results in higher noise levels in the vicinity of the work area. As projects that employ efficient microtunnelling systems can be completed faster, the noise pollution cost is lowered and the impact on residents is reduced.
Worker safety can also be improved by employing trenchless technologies such as microtunnelling. The large amount of excavation required for open cut methods of pipeline installation creates a greater safety risk to workers and increases the chance of public interference, especially in urban areas.
Microtunnelling requires minimal excavation so there is less chance of safety problems arising from trenches. The AXIS guided boring system is the only microtunnelling machine on the market that has been designed with unique safety features to offer a superior level of operator safety and reduce the risk of materials falling into the pit and hurting workers.
For more information go to the Edge Underground website.
This article appeared in the February 2022 issue of Trenchless Australasia. Click here to view the digital edition of the magazine.