Unemployment figures released yesterday may have showed little change in the nation's jobless rate, but it appears there's a gaping hole in the statistics when it comes to earthquake struck Christchurch.
The sequence of earthquakes that has greatly affected Christchurch and Canterbury since September 2010 has again demonstrated the need for seismic retrofit of heritage unreinforced masonry buildings. Commencing in April 2011, the damage to unreinforced stone masonry buildings in Christchurch was assessed and recorded with the primary objective being to document the seismic performance of these structures, recognising that they constitute an important component of New Zealand’s heritage architecture. A damage statistics database was compiled by combining the results of safety evaluation placarding and post-earthquake inspections, and it was determined that the damage observed was consistent with observations previously made on the seismic performance of stone masonry structures in large earthquakes. Details are also given on typical building characteristics and on failure modes observed. Suggestions on appropriate seismic retrofit and remediation techniques are presented, in relation also to strengthening interventions that are typical for similar unreinforced stone masonry structures in Europe.
The M7.1 Darfield earthquake shook the town of Christchurch (New Zealand) in the early morning on Saturday 4th September 2010 and caused damage to a number of heritage unreinforced masonry buildings. No fatalities were reported directly linked to the earthquake, but the damage to important heritage buildings was the most extensive to have occurred since the 1931 Hawke‟s Bay earthquake. In general, the nature of damage was consistent with observations previously made on the seismic performance of unreinforced masonry buildings in large earthquakes, with aspects such as toppled chimneys and parapets, failure of gables and poorly secured face-loaded walls, and in-plane damage to masonry frames all being extensively documented. This report on the performance of the unreinforced masonry buildings in the 2010 Darfield earthquake provides details on typical building characteristics, a review of damage statistics obtained by interrogating the building assessment database that was compiled in association with post-earthquake building inspections, and a review of the characteristic failure modes that were observed.
Questions to Ministers 1. CRAIG FOSS to the Minister of Finance: What challenges does the Government face in putting together Budget 2011? 2. Dr RUSSEL NORMAN to the Prime Minister: Does he stand by his pre-Budget statement "The key sector which is not saving right now is the Government"; if so, what steps has he taken to increase government revenue? 3. Dr RUSSEL NORMAN to the Prime Minister: Does he stand by his statement "…we can use this time to transform the economy to make us stronger…"; if so, does this transformation involve an economy that uses fewer natural resources and produces less pollution? 4. Hon PHIL GOFF to the Prime Minister: Does he stand by all his statements on KiwiSaver? 5. NICKY WAGNER to the Minister for Canterbury Earthquake Recovery: What reports has he received on progress made to provide winter heating for residents affected by the Canterbury earthquakes? 6. Hon ANNETTE KING to the Prime Minister: What advice did he receive from the most recent food bank he visited about the current cost of living? 7. JACQUI DEAN to the Minister for the Environment: What practical initiatives is the Government taking in preparation for Rugby World Cup 2011 to protect the environment and New Zealand's important clean green brand? 8. Hon DAVID CUNLIFFE to the Minister of Finance: What was the annual rate of GDP growth for the year ended December 2010 projected in Budget 2010, and what was the actual rate of growth for that period according to Statistics New Zealand? 9. AARON GILMORE to the Minister of Education: What recent decisions have been made regarding schooling in Christchurch? 10. SUE MORONEY to the Minister of Education: When was construction completed on the new early childhood education centre at Weymouth Primary School and why is the centre empty? 11. COLIN KING to the Minister of Agriculture: What steps has the Government recently taken to support innovation in the Manuka honey industry? 12. CARMEL SEPULONI to the Minister of Justice: Does he stand by his statement "This Government is committed to ensuring that everyone…has access to justice"?
Six months after the 4 September 2010 Mw 7.1 Darfield (Canterbury) earthquake, a Mw 6.2 Christchurch (Lyttelton) aftershock struck Christchurch on the 22 February 2011. This earthquake was centred approximately 10km south-east of the Christchurch CBD at a shallow depth of 5km, resulting in intense seismic shaking within the Christchurch central business district (CBD). Unlike the 4 Sept earthquake when limited-to-moderate damage was observed in engineered reinforced concrete (RC) buildings [35], in the 22 February event a high number of RC Buildings in the Christchurch CBD (16.2 % out of 833) were severely damaged. There were 182 fatalities, 135 of which were the unfortunate consequences of the complete collapse of two mid-rise RC buildings. This paper describes immediate observations of damage to RC buildings in the 22 February 2011 Christchurch earthquake. Some preliminary lessons are highlighted and discussed in light of the observed performance of the RC building stock. Damage statistics and typical damage patterns are presented for various configurations and lateral resisting systems. Data was collated predominantly from first-hand post-earthquake reconnaissance observations by the authors, complemented with detailed assessment of the structural drawings of critical buildings and the observed behaviour. Overall, the 22 February 2011 Mw 6.2 Christchurch earthquake was a particularly severe test for both modern seismically-designed and existing non-ductile RC buildings. The sequence of earthquakes since the 4 Sept 2010, particularly the 22 Feb event has confirmed old lessons and brought to life new critical ones, highlighting some urgent action required to remedy structural deficiencies in both existing and “modern” buildings. Given the major social and economic impact of the earthquakes to a country with strong seismic engineering tradition, no doubt some aspects of the seismic design will be improved based on the lessons from Christchurch. The bar needs to and can be raised, starting with a strong endorsement of new damage-resisting, whilst cost-efficient, technologies as well as the strict enforcement, including financial incentives, of active policies for the seismic retrofit of existing buildings at a national scale.