The head of the engineering company that designed the Canterbury Television building says a report on the building's collapse is ''technically inadequate''.
The Department of Building and Housing today released its report into the CTV building; the building collapsed and caught fire in the February 22, killing 115 people.
Alan Reay Consultants Ltd (ARCL) designed the CTV building in 1986, and director Alan Reay said he disagreed with several of the report's findings.
''Personally, I feel incredibly torn,'' he said.
''I have huge empathy for the families waiting for answers, but these reports are technically inadequate. We owe it to the families of those who died in the CTV building to conduct a robust and thorough investigation using the best technologies and methodologies available. This has not occurred.
''ARCL is extremely disappointed with the process the DBH has followed and the subsequent conclusions in the reports. It has not carried out the investigations it should have.
''Some of the assumptions made in the reports are highly questionable. As a consequence, the report's findings are not conclusive. In fact, in many areas they may be flawed.''
The conclusion that columns in the building were the primary cause of its collapse was the most concerning aspect, he said, ''given the limited forensic investigation undertaken by the DBH''.
''Investigations of the columns and shear walls, using more appropriate investigative analysis and methodology, must be a priority to determine if they indeed played a role in initiating the building's failure.
''We need to remember that the standards of the day, when the building was designed and constructed, were not intended to withstand the magnitude and type of earthquake, together with the resulting vertical acceleration, experienced on February 22.''
POLICE SEEK LEGAL ADVICE
Police are seeking legal advice over a Government report into the CTV building's collapse in last February's earthquake.
The Department of Building and Housing said the design and construction of the CTV building did not meet building standards when it was constructed.
It found the building collapsed because of three critical factors - the building's failure to bend sufficiently during the quake (it was brittle), the poor strength of key support (shear) walls, and layout of those walls - none of which met building standards at the time, Department of Building and Housing chief executive Katrina Bach said.
Police assistant commissioner Malcolm Burgess said police would be seeking legal advice and assessment of the department's evidence, which would determine the next step.
He said it would be wrong to suggest the assessment would naturally lead to criminal charges.
CTV was the largest single site of tragedy in last February's earthquake, which killed 184 people.
Earthquake Recovery Minister Gerry Brownlee said the report will be tough for the families and friends of those who died.
"This news will be painful for the families, colleagues and friends of the 115 people who lost their lives in the collapse of the CTV building. Our thoughts are with them on this difficult day.
"[The report] raises some serious questions about the structural integrity of the building.''
The ductility of the columns, the asymmetrical layout of shear walls and the column shear strength did not meet the standards of the day in 1986 when it was built and were critical factors in the collapse of the CTV building, according to the report.
The other critical factor in the collapse was because of the intensity of horizontal ground shaking.
The report states if the CTV Building had been built to current requirements it was unlikely that it would have collapsed in the way that it did as evidenced by the performance of the most modern buildings in Christchurch.
Current building requirements were more stringent now than in the 1980s as standards have progressively
improved over time as more is understood about how buildings respond in earthquakes.
The report found the building was robust enough to resist the effects of the September 4, 2010 earthquake and the December 26, 2010, aftershock with significant damage. However, the demands on the building on February 22 2011 "greatly exceeded those anticipated in the structural design of the building".
Tests on more than 21 per cent of CTV's columns after the collapse found that concrete in "many columns were
significantly weaker than expected", according to the report.
While it was not possible to be definitive on the collapse sequence, the likely scenario was the building tilt east after
an initial failure by one or more columns on the mid to upper levels on the east face, it said.
Intense horizontal ground shaking, non-ductile columns and the asymmetrical layout of shear walls were critical factors in the collapse of the Canterbury Television Building.
Other factors which could have contributed to the CTV collapse included; low concrete strengths, vertical ground
accelerations, interaction of columns and spandrels, separation of floor slabs from the north core and
structural influence of masonry walls.
Investigation project manager and structural and seismic engineer Dr David Hopkins said the investigation
was to find out how the collapse happened.
REPORT'S FINDINGS 'DEVASTATING'
Building Minister Maurice Williamson said the report made recommendations in five key areas of design and construction.
''[DBH] has already taken action on some and plans have been made to implement the other recommendations across the building and construction sectors.''
The CTV report is the fourth and final investigation by DBH into the failure of key buildings in central Christchurch last February, which included the Pyne Gould Corporation building, Forsyth Barr, and the Hotel Grand Chancellor.
Labour Earthquake Recovery spokeswoman Lianne Dalziel said the report's conclusions were ''devastating''.
''The report has revealed that the building was not built to code - a devastating finding considering the collapse of this building was responsible for more than 60 per cent of the deaths in the earthquake.
''It won't be easy for [family and friends] to learn that the collapse has now been referred to the police, as they will now have to wait for final decisions on what happens next.''
The report's release prompted Local Government New Zealand (LGNZ) to renew its call for a tougher national standard for strengthening earthquake prone buildings.
''A stronger national specification...avoids uncertainty,'' LGNZ president Lawrence Yule said.
''Currently the law only sets a minimum standard for retro-fitting earthquake prone buildings. LGNZ believes this encourages building owners to just do the minimum.''
Strengthening older buildings, especially heritage ones, was complicated and often expensive, Yule said.
''People need to consider how much they value the older buildings in their community, and how that influences their concerns about building performance in an earthquake.''
Families of those who died in the building and its tenants were briefed earlier today on the contents of the long-awaited report.
Geoff Brien, of Fendalton, whose wife, Pam, died in the CTV building, attended today's briefing.
He said it was "very interesting" and showed the building was "not good" before the quake.
The report was "really thorough" and "really well done", he said.
He would not go into details about the contents of the report, but said he was celebrating.
His wife had been a member of the Christchurch police child-protection team based at the Papanui station. Her police career began in New Plymouth, and she moved to Christchurch in 2001.
Yesterday, Brien said he hoped the report would pinpoint the cause of the collapse and that someone would be held to account.
"I'm a self-employed contractor, I've worked for myself since I was 18 years old and if I do something wrong I've got to fix it," he said.
Family members of the 28 Japanese victims are considering legal action over the CTV building's failure.
"Good luck to them; I'm right behind them," Brien said.
He said the first anniversary of the February 22, 2011 quake would prompt mixed emotions, and he did not know how he would spend the day. He did not think he would attend official events in Hagley Park.
The Government originally asked the department to provide technical reports by July 31 last year on the collapse of the CTV, Pyne Gould Corporation, Forsyth Barr and Hotel Grand Chancellor buildings.
Reports on the last three buildings were released in September.
The department last year cited unforeseen "complications" for the delay of the CTV building report.
The report is crucial to the earthquakes royal commission's inquiry, and the delay in its release has forced the commission to seek an extension from the Government on its final report.
The commission now has until November 12 to finish its investigation.
Department building quality deputy chief executive David Kelly has said the CTV building's complex design was responsible for the delay, throwing up multiple scenarios for how the building collapsed that needed to be run through a complex computer model.
- The Press