Events carry on whilst Albert Park stabilised
24 November 2005
Work to stablise Albert Park allows events to go on
Engineers are working to stablise Albert Park by using heavy granular material to fill in old ventilation shafts that lie beneath the reserve's surface.
Auckland City commissioned the remediation work after a geotechnical investigation found that a number of the ventilation shafts were not properly filled with compacted soil.
The ventilation shafts were built during World War II to feed a tunnel system below the surface of the park that was originally designed as an air raid shelter.
In September, there were two cases of subsidence in the park. In both cases, this was due to the slow settling of soil used to fill the shafts many years ago.
The geotechnical investigation found that soil had settled in five of the six ventilation shafts in the park. This has typically left a void of about one to two cubic metres at the top of each filled shaft.
Auckland City parks officer, Graham Marchant, says at least $80,000 worth of remediation work is needed to stabilise the park and to provide a permanent monitoring system.
"Albert Park is a popular sanctuary in the middle of the city and it's important that we ensure the area is completely stable. Filling in these old ventilation shafts will be a simple process that will not affect users of the park."
Engineers also discovered that a concrete cap used to seal-off one of the shafts was broken and needed to be replaced. Mr Marchant says putting a new cap on top of this ventilation shaft means a small area of the park near the Band Rotunda will remain fenced off while work is carried out.
He says permanent access points are being created above each of the ventilation shafts, so that they can be regularly checked and corrected without further excavation.
The heritage status of the World War II tunnels, barracks and ventilation shafts means that all engineering work needs to be carefully monitored.
The council's city heritage manager, George Farrant says, "One of the beauties of Albert Park is its long and multi-layered history and we've worked hard to make sure that is protected.
"We have liaised with the engineers to ensure they can do their job while keeping the integrity of the shafts, the tunnels and the park intact. We've also strived to reduce the need for future intervention into this sensitive archaeological site."
Mr Marchant says construction work should be complete before the summer events season, so that popular events like the Chinese Lantern Festival and the 95 bFM Summer Series can go ahead at the park.
"We're thrilled that the construction work will not take too long so that people can continue to enjoy the park throughout the summer months. Albert Park is a popular site for large events and they can now go ahead unimpeded," he says.