Pacific Tower to reopen by February
The owner of the 22-storey Pacific Tower, home of the Rendezvous Hotel, says the central Christchurch building will reopen before the second anniversary of the February 22 quake.
Owner Ernest Duval said he wanted to ensure the building was back to its full strength, but he was also conscious that its hotel tenant and owners of apartments on the building's top floors had already been out of the building for more than a year.
He has set a deadline of February 22 to have the building open and the hotel trading.
"And if that means people working extended shifts, seven days, or through holidays that will happen," he said.
The Rendezvous had hoped to reopen back in March, but that was postponed while the building was rechecked at the request of the Canterbury Earthquake Recovery Authority. Since then, repair work has continued on the Gloucester St building.
The February earthquake had stressed steel links in the structure, weakening them, and breaking four.
The links are at the joins of structural steel beams.
Although most were still well within safe strength levels, he intended to replace many of the weakened links so they were at the same level as before the quakes.
Steel was different to other materials, the damage was not immediately obvious and only testing could determine how the strength of the steel had been affected, he said.
When steel is stressed it becomes harder, but more brittle, until snapping point.
Three engineers, including the building designer and foremost Kiwi steel engineering expert University of Auckland professor Charles Clifton, have tested several links to create a model to determine how the quake would have affected each within the building.
Several links would be replaced, however, Duval could not say how many. Some links could have lost a small proportion of their strength, although they would be safe even if they lost a similar amount again. However, because further stress on the links would accumulate, he wanted to have as many replaced to full strength as possible.
The work would need to be submitted to his insurer and approved.
Meanwhile, a contractor was pricing up all the links - a complicated exercise because some of them were right inside the building, Duval said.
"It will be like laparoscopic [keyhole] surgery on a person. They'll have to access the links, remove the linings, remove the links and put in new ones."
Because the replacement involved cutting steel and welding, the work would need careful planning to ensure proper ventilation for workers, among other considerations.
The cost of replacing the links, using a "very high case" estimate, would be about 10 to 15 per cent of the building's replacement value, he said.
The building, reportedly costing $50 million to build in 2008-09, opened in 2010.
Once finished, the building would be back to 100 per cent of the new building code and would show Christchurch developers and builders that high-rise buildings could be made "to withstand the force of some of the strongest earthquakes we've ever known", he said.