What to do with Australia’s vast ageing drainage network? Trenchless pipe rehabilitation is a fraction of the cost compared to the excavation and the construction of a replacement drain in built up areas.
Reinstatement of paved surfaces and returning the street scape can be significantly more than the drain’s cost component.
The modern-day drainage budget
To dig and lay provides an asset owner the reassurance of another 50 years plus design life, but it is expensive. Pit to pit trenchless drain rehabilitation lessens the impact of a civil open trench upgrade. Advanced cleaning and robotic cutting equipment, coupled with high end CCTV pipe cameras, are readily available Australia wide.
High quality technology opens up the ability to provide comparable longevity in drain rehabilitation at a reduced cost. Sectional and full relining use materials that provide the asset owner with a higher coefficient in the pipes surface, increasing flows. As a bonus, modern rehabilitation technology and installation techniques exploit what once was regarded as near impossible, or “extreme measures”, to a viable solution.
Today pit to pit relining and sectional pipe repairs are all rated well beyond a 50 year service life, assisting in the accountability to maintain the life cycle of an asset. If we think of the oldest successful drain specification – that being a fired or even a non-fired clay pipe – we know that it enjoyed a long service life but was heavily reliant on strong pipe joints. A major issue today is root intrusions at the pipe joint and unwelcome drain movement. When this movement continues over the assets lifespan it generally results in cracks and increasing displacements. Further to this issue is the physical abrasive wear factors and, in sewer systems, H2S gas attack of the concrete itself.
Drainage network maintenance program
In most cases where the pipe surface remains serviceable but for only a few defective joints, the pipe section is often left to become a maintenance liability. This section may be marked up after a few years of random response cleaning to qualify for the routine cleaning list. Once there, it is left on an ongoing basis. When cleaning cycles over many years have passed it progresses, heading away from maintenance as it arrives usually onto the reline or replace pipe register.
Clean & camera of known drainage chokes
High-pressure water jet clearing of reoccurring blockages in drainage assets can, in some cases, increase root intrusion growth and further destabilise pipe bedding, which impacts a defect further. The most effective solution is to reopen a drain, but without a CCTV vision review an opportunity window to rehabilitate may pass by. A pipe section may simply require a morning’s effort of cleaning and some simple point or sectional pipe repairs. If the CCTV assessment finds multiple issues resulting in many pipe defects the drain may be ideally suited to a full length reline.
Typically speaking, drainage officers prefer a full reline when the rehabilitation of sectional repairs range between 50-70 per cent of the reline cost. The high impact raise and lay replaces cost that are reserved only for those drainage sections that warrant the upgrade.
Providing valuable trenchless solutions
The Smart Lock Group is a product supplier to drainage rehabilitation contractors and local government pipe maintenance crews alike. With industry knowledge and experience in pipe rehabilitation, its drain defect solutions begin with 100 mm to 900 mm pipes, engaging the use of various installation packer-style trolleys. In larger pipes it provides confined space entry pipe rehab solutions. All products are approved and are true structural trenchless repairs.
For more information visit the Smart Lock Group’s website.
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This article appeared in the October edition of Trenchless Australasia. Access the digital copy of the magazine here.