Earthquake lessons to reduce risks


By Romy Udanga

Win ClarkEarthquake experts are looking to update the Guidelines on the Assessment and Improvement of the Structural Performance of Buildings in Earthquakes in support of the Department of Building and Housing’s recommendations, following its technical investigation into the failure of the large multi-storey Pyne Gould Corporation (PGC), Forsyth Barr and Hotel Grand Chancellor buildings during the February 22 Christchurch earthquake.

New Zealand must apply lessons from the investigations into the Canterbury building failures to drive progress and reduce risks from earthquakes in the country, earthquake engineers say.

New Zealand Society for Earthquake Engineering executive officer Win Clark says the society agrees with the DBH’s findings, released last month, which cite extremely strong ground shaking as one of principal reasons why the three buildings failed as well as noting that at the time they were constructed, design requirements were less well understood than they are today.

DBH has also released its report to the Minister for Building and Construction outlining its response to the findings, including urgent priority actions recommended by the expert panel that undertook the investigation.

The reports are seen to provide vital information to the Royal Commission of Inquiry into Building Failure Caused by Canterbury Earthquakes.

Clark says the lessons "must be learned from, addressed and applied".

He says the investigation has been extremely thorough, conducted by leading New Zealand expert engineering consultants whose findings were then peer reviewed by a panel including experts of international experience and standing—more than half of which are NZSEE members.

"One recommended priority action from the investigation is that lessons from the Canterbury earthquakes be incorporated into the Guidelines on the Assessment and Improvement of the Structural Performance of Buildings in Earthquakes," Clark says.

The Guidelines are published by NZSEE and were updated with the support of DBH in 2006. They have been used by most city and district councils and consultants in New Zealand when assessing their earthquake-prone buildings and remedial actions as required by the Building Act.

Clark says NZSEE was planning to update the guidelines using feedback from members and new research findings before the September 2010 Darfield earthquake.

He says the guidelines will now be updated to include findings from the DBH’s technical investigations and from the report by the Royal Commission, expected next year, "which will add further recommendations, relevant across New Zealand."

Clark says NZSEE members have investigated significant earthquakes in New Zealand and from around the world for nearly 50 years, gaining vital knowledge which has improved New Zealand’s earthquake resilience.

Their investigations have resulted in improved building statutes, construction practices, and in establishing lifeline engineering, urban search and rescue (USAR), and the red, yellow and green building assessment procedures following an earthquake, he says.

"Consequently while there was significant tragic loss of life from the earthquake of February 22, we know from overseas examples that it was far less than it otherwise may have been.

"We owe it to those that lost their lives or suffered injury in Canterbury to identify the lessons for New Zealand from that tragedy through further investigation, research, and through the Royal Commission’s findings, and to learn from those lessons, address them and apply them with urgency."

NZSEE works with other professional societies, IPENZ and other relevant organisations and agencies.

"We will continue our nearly five decades of active advocacy for the public of New Zealand, to drive progress and reduce risks from earthquakes," Clark says.