Utilities are increasingly aware of the impact of pipeline installations on the surrounding environment. While all trenchless methods involve minimal impact there is a microtunneling system available that takes this one step further.
According to Stuart Harrison, Managing Director of Edge Underground, microtunnelling with machines such as the AXIS guided boring system has a number of benefits that limit damage and destruction to the surrounding environment, flora and fauna. This includes reducing site footprint, shorter restoration times, and low carbon emissions.
Reduced site footprint
“Trenchless technologies such as microtunnelling operate within a smaller site footprint than traditional open-cut trench projects,” Mr Harrison said.
“Microtunnelling involves the excavation of an entry and exit pit, with the ground between these points left undisturbed throughout the installation process.
“As disruption to the ground is kept to a minimum, the impact to the surrounding environment, flora and fauna is greatly reduced, and contractors are able to get the job done quicker than if full trenches are used. ”
The AXIS system provides further benefits due to its extraction methods.
“In the past, pilot lines were predominantly installed via a displacement method. For this method to be successful, the ground being tunnelled through must be displaced, which has the risk of disturbing the ground surrounding the installation, causing unnecessary damage to the environment,” Mr Harrison said.
“Unlike traditional methods, the AXIS systems 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.”
The AXIS system also utilises 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 key-hole solution
Using the AXIS system, Mr Harrison has been able to complete projects that were required to be extremely precise and noninvasive using key-hole pipelining with microtunnelling.
While open-cut methods scar the terrain as adversely as open-heart surgery on a patient, key-hole pipelining can be likened to key-hole heart surgery – a safer, cleaner alternative. As minimal ground incision is needed for a pipe to be installed, there is minimal disruption to the ground and any services and obstacles around the pipeline.
Shorter restoration times
“As the AXIS system only requires minimal excavation it is able to minimise restoration time and costs,” Mr Harrison said.
“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. Not only does this reduce the impact on the environment but it is also more cost-effective.”
Low emissions
The AXIS system has been proven to have low carbon emissions.
During a project in the US which used the AXIS system, Dr Sam Ariaratnam and his team at Arizona State University did an emissions study utilising the ‘E Calc’ emissions calculator. The study compared the results to alternative methods, with the AXIS system conclusively presenting the least emissions of the methods.
“With the environmental impact of pipe installations becoming an important consideration for utilities, the Vermeer AXIS guided boring system provides a solution that has minimal impact and remains cost competitive,” Mr Harrison said.