There were cheers all around when the final load of sand to form the base for Brisbane Airport’s New Parallel Runway was pumped onto the runway site over the weekend – some two months early.
Julieanne Alroe Brisbane Airport Corporation (BAC) CEO and Managing Director said collaborative project management and detailed planning contributed to the completion of this stage of the project, well ahead of schedule.
“This is a milestone moment and a credit to BAC’s New Parallel Runway team and the team from Jan de Nul delivering this critical stage of our new runway so efficiently while maintaining the environmental credentials of Moreton Bay, the safety of everyone working on the site and airport operations,” she said.
“It is no coincidence, rather a result of years of intense planning and constant and consistent attention to detail at all stages of the project. I applaud each and every person involved for their commitment and hard work.
“The NPR is a significant piece of infrastructure for our airport, for our city, for our state and for our nation.By 2030, over $5 billion of economic benefits will be brought into this immediate region as a result of the increased capacity that this runway system will give us.
“When complete, Brisbane Airport, without any doubt, will be the most efficient airport in Australia and amongst one of the most efficient airports in the world,” Ms Alroe said.
Paul Coughlan Project Director NPR said the new runway was being built on swamp land which needed to be stabilized prior to the next phase of construction.
“The runway site was once part of the Brisbane River delta and one of the key challenges has been to consolidate the existing soft subsoils on the site which has the consistency of tooth paste.
“The sand platform on the worst ground conditions measures eight meters above the original ground level which will be left to compact for the next two to three years with some sections of the site already settled by over one meter,” Mr Coughlan said.
Dredging began on June 4 and favorable weather over the last six months allowed the Belgian dredge Charles Darwin to pump ashore nearly 11 million cubic meters of sand from the dredge site at Middle Banks adjacent to the main shipping channel in Moreton Bay.
The Charles Darwin, one of the most modern and powerful dredges in the world, has been working 24 hours a day, seven days a week, averaging three round-trips per 24 hour cycle.
It has pumped an average of 70,000 cubic meters onto the site each 24 hour cycle – which would otherwise have taken a convoy of heavy trucks stretching 126 kilometers to deliver each and every day.
In total, the dredge has made 467 trips and the final sand pump marks the beginning of the end of Phase One of the $1.3 billion project, which began in August 2012 with the felling, clearing and mulching of casuarina trees on the 360 hectare site. The mulch was mixed with topsoil and has been stockpiled on site for use in the final landscaping of the new runway.
Nearly 10 kilometers of new drains, designed to convey all run-off from the new runway and taxiways into the Kedron Brook Floodway, were constructed and, as with the existing runway, which remained open during the 2011 floods, the site has been engineered to withstand a once-in-100-year flood event.
The site is being drained with the aid of 330,000 individual wick drains punched into the ground to a depth of up to 30 meters – the largest wick drain project ever in Australia. Laid end to end the individual wicks would total 8,000 kilometers – nearly the equivalent distance from Brisbane to Beijing.
In the softest areas of the site the wick drains have been spaced as close as one meter apart. In combination with the weight of the sand they will hasten the draining and settlement of the site which will be left to consolidate over the next three years.
Work on Phase 2 of the project – finalizing the design and layout of the airfield, taxiways, airfield lighting and navigational aids, is already well underway.
Brisbane’s New Parallel Runway is due to become operational in 2020.