In 2016, Western Australia’s Water Corporation embarked on a three-year program to improve the security and reliability of Perth’s water supply called Pipes for Perth. The utility identified a need to renew ageing cast iron pipe infrastructure, with some sections of Perth’s water main network now over 100 years old and showing signs of wear and tear.
Pipes for Perth was established to proactively replace these pipes to avoid future bursts and leaks. A range of methods are being used to replace and renew the vital assets, including the trenchless methods of sliplining and pipe bursting.
While traditional open cut excavation is often viewed as tried and tested, open excavation does come with the potential downsides of lengthy disruptions to stakeholders and construction programs, noise, dust and often significant issues excavating in congested underground service corridors. These activities can put other services at risk of disruption or result in costly rerouting of the new pipeline to avoid them.
Water Corporation and its contractors had to consider these challenges when they were faced with replacement of approximately 650 m of DN 200 and DN 100 cast iron water main, with 250 OD and 125 OD PE pipe, on Scarborough Beach Road and Hobart Street in the suburb of Mount Hawthorn, 5 km north of Perth’s CBD. The section of pipeline could not be sliplined as a critical requirement of the project was that they be upsized.
The situation was complicated further by the busy, narrow and picturesque streetscapes filled with local businesses, such as the iconic and historic Paddington Ale House, a popular watering hole for locals that is more than 80 years old. The underground service corridor was also congested, with no room for a new pipeline. Excavation would have also resulted in significant disruptions to businesses, residents and road users.
As a result of the predicament, the principal contractor engaged pipeline rehabilitation specialists ITS PipeTech to design a solution that used the existing pipeline, without significant disruption to existing stakeholders and services. ITS proposed its well proven pipe bursting technology for the project.
First developed in the UK, pipe bursting has been used since the late 1970s and is now an internationally recognised and accepted trenchless pipeline replacement method. It minimises the need for excavation by reusing the existing pipeline, instead of removing and replacing.
Pipe bursting uses a bursting head that is winched from an entry to an exit pit, fracturing or splitting the existing pipe while it tows a new PE pipe of a similar or larger diameter into place. Compared with traditional excavation methods, pipe bursting uses a reduced site footprint and lessens the impact of construction on stakeholders, restoration and the environmental.
During the course of the project, ITS PipeTech was able to maintain water and traffic flows, ensuring no significant disruption to stakeholders. In addition, all other existing services were maintained without disruption.
This article was featured in the September edition of Trenchless Australasia. To view the magazine on your PC, Mac, tablet, or mobile device, click here.
For more information visit the ITS PipeTech website.
If you have a project you would like featured in Trenchless Australasia contact Managing Editor Nick Lovering at nlovering@gs-press.com.au