Statistics House quake performance unacceptable, inquiry finds; building rules may be tightened
By Sophie Boot
March 31 (BusinessDesk) - Wellington's Statistics House performed unacceptably in the November Kaikōura earthquake and
could have caused fatalities, an independent investigation has found.
Two floors of the building partially collapsed in the Nov. 14 earthquake, and the building was declared a no-go zone the
next morning, with entry prohibited since. The investigation, commissioned by the Ministry of Business, Employment and
Innovation, didn't consider the future use or reparability of the Statistics House building.
The independent panel's investigation found that four factors contributed to the partial failure of lower floor
segments: the high level of flexibility in the building’s design, the precast style of floor construction, the magnitude
and duration of the 120-second earthquake, and the amplification of ground shaking by the geological basin beneath
Wellington.
"This quake was large and unusually long but a modern building like Statistics House should not have had
life-threatening structural damage," Building and Construction Minister Nick Smith said. "The building was designed to
the industry practice of the time but this did not fully account for the effects of beam elongation during an
earthquake, an issue that was deficient in the Concrete Structures Standard at the time of the design."
The building's fourth floor had had remedial work done after the Canterbury earthquakes after a seismic review
identified potential performance issues, and that part of the building performed well in the Kāikoura earthquake.
The panel made four recommendations. It said existing buildings in the Wellington region with a similar design that may
have been damaged by the Kaikōura earthquake should be investigated for problems, and the industry should be notified
about issues with precast floor systems. MBIE should also access technical expertise to consider the implications for
this type of design for new buildings, and should review and undertake research into the provisions in the Earthquake
Actions standard to ensure they reflect current knowledge, it said.
Smith said the government will amend the Concrete Structures Standard this year to ensure new buildings can cope with
beam elongation during earthquakes, and he has asked MBIE to report whether it needs additional powers under the
Building Act to require building owners to follow up on problems.
"The largest safety gains for Wellington are to be made in the initiatives requiring unreinforced masonry facades and
parapets to be tied back over the next year and all earthquake-prone buildings under 34 per cent of Building Code to be
upgraded under the new law coming into effect on July 1," Smith said.
(BusinessDesk)