Commission Faults Designer, Engineer for Christchurch Building's Collapse
When the six-story CTV building fell within 20 seconds after a 6.2-magnitude earthquake struck the city on Feb. 22, 2011, 115 of its occupants died.
The final reports of the Canterbury Earthquakes Royal Commission have explained why the CTV building in downtown Christchurch, New Zealand, collapsed during a strong Feb. 22, 2011, earthquake, killing 115 of its occupants. Only a handful of people inside the building at the time survived. The commission has issued its reports in stages, and the last ones blame inadequate design of the building by David Harding in 1986 and criticize Dr. Alan Reay, an engineer, for letting Harding work unsupervised.
"We also consider that Dr Reay was aware of Mr Harding's lack of relevant experience and therefore should have realized that this design was pushing him beyond the limits of his competence. Dr Reay should not have left Mr Harding to work unsupervised on the design or without a system in place for reviewing the design, either by himself or someone else qualified to do so. The process led to a building design that was deficient in a number of important respects," the summary section of the sixth report states.
In this section, the commission also says Reay's involvement in the permitting process contributed to having a building permit granted for the building even though it did not comply with best practices or with the Christchurch City Council's Building Bylaw 105, which covers general structural design and design loadings for buildings. This section adds that there is "no reliable evidence" suggesting the concrete used in the building's columns was of insufficient strength.
The document says witnesses described that the building twisted as the earthquake began, followed by "a brief period when the initial twisting appeared to stop, a tilt towards the east, a vertical jolt and the building pancaking, all of which took place very soon after the shaking started. We have concluded that the collapse was completed within 10-20 seconds of onset of the earthquake."
The report also contains recommendations for examining other buildings in New Zealand for their potential seismic performance.
Kurt Bayer of The New Zealand Herald reported Dec. 11 that Reay, Harding, and construction manager Gerald Shirtcliff had declined to comment on the commission's report, saying either they had not received a copy of it or had not yet read it thoroughly.