The looping project recently commenced at Preston Road in Carina, Queensland, and is set to terminate at Paringa Road, Murarrie. The line is currently being constructed using 400 mm diameter X70 grade DFBE-coated pipe and runs parallel to the existing line, crossing it at a number of locations.
As part of the contract, the Pipeline Drillers Group initially assisted APA Group in planning the construction of the horizontal directional drilling (HDD) along the route and, having worked successfully with WDS Limited on a number of previous pipeline projects, WDS was happy to subcontract the HDD operation to the Pipeline Drillers Group, who currently has three rigs committed to the project.
Challenges in wild Queensland
The terrain in which the looping project is being undertaken is generally low lying and is therefore susceptible to flooding and tidal influence for much its length. According to WDS, groundwater could be a problem for the project, together with the associated impacts of acid sulphate soil. Mangroves and areas of marine couch and sedges are also evident along the route and special measures have been adopted to preserve these as much as possible.Article continues below…
In order to cross the Gateway Arterial Road, Lytton Road, the Port of Brisbane Railway line and numerous other environmentally sensitive areas associated with tributaries of Bulimba Creek, the use of HDD was a must. A total of nine HDDs have been required throughout the duration of the project, totalling approximately 40 per cent of the length of the pipeline.
Urbanisation has also encroached alongside the original right-of-way, meaning that special consideration has had to be given to construction access and methods with street works. In order to accommodate this issue, some of the construction has needed to be undertaken at night to lessen disruption to enterprises along the line.
However, WDS is working closely with APA throughout the project and has not encountered any unforeseen issues at this point.
According to WDS Limited, there are a number of reasons that have made HDD an optimal method of construction for various sections, including:
- Crossing environmentally sensitive areas such as sections of mangroves and watercourses associated with Bulimba Creek;
- Crossing sections of community parkland infrastructure at Minippi Park off Pearson Road; and,
- Traversing under motorways, railway lines and roads.
The Pipeline Drillers Group has had three rigs working on the project, namely a Vermeer–100/120; a Vermeer–330; and a CMS–180.
With the three rigs now employed it is anticipated that the HDD operations will be completed by the end of June 2012.