Earthquake safe building

The following articles help to demonstrate that Russell Properties houses are constructed using some of the safest building methods around and, combined with a modern building code, will provide safe houses in the event of an earthquake.

The building collapses in the Christchurch Earthquake were primarily due to ground instability, old construction methods and materials. These had been constructed under an old Building Code.

Ground Stability

ALL of Russell Properties sites are tested by a Geotechnical Engineer, and this information is forwarded to the Wellington City Council as part of the building consent process.

For your information, geotechnical engineeringis the branch of civil engineering concerned with the engineering behaviour of earth materials. Geotechnical engineering uses principles of soil mechanics and rock mechanics to investigate subsurface conditions and materials; determine the relevant physical/mechanical and chemical properties of these materials; evaluate stability of natural slopes and man-made soil deposits; assess risks posed by site conditions; design earthworks and structure foundations; and monitor site conditions, earthwork and foundation construction. – Wikipaedia 05/11.

Building Performance

Click to read an article from Branz Building magazine 123 April/May 2011 about the performance of buildings after the Christchurch earthquake of 22 February 2011.

Click to read an article from Building Today about the performance of buildings build under different building codes.

Building with brick

Christchurch’s ‘Wall of Hope’ Still Stands

The 25sq m freestanding ‘Brick Art’ mural which was unveiled on the 8th of February 2011 at the corner of Victoria and Salisbury Street has stood strong through the recent earthquake and aftershocks.

At the unveiling Christchurch Mayor Bob Parker referred to the mural as “a wall of hope for Christchurch”.  The mural features a bricklayer at work to represent the ‘dawn of the new day’. Austral Bricks created the mural to send a positive message to Canterbury about rebuilding and to raise funds to rebuild the Child Cancer Foundation Christchurch Family Place, which was severely damaged in the September earthquake.

“The fact that this mural has survived a major earthquake that has caused so much devastation is testament to how modern bricklaying techniques and engineering can perform,” explained Canterbury Brick and Blocklayers Association President Bernard Caddick.

“The mural's steel frame was engineered with the possibilities of earthquakes in mind although we laid the bricks as we would on any other project. The wall is 5 metres high by 5 metres wide with no side bracing and it is supported by a well engineered steel frame which is set in concrete foundations.”

“Our city's streets are littered with bricks. However it is important for people to understand that many of these buildings were constructed in a very different way than the techniques we use now. The building standards have evolved and bricklaying techniques have changed as we understood more about how buildings react under immense pressure such as an earthquake.”

Over the last two years, the brick industry has been working with BRANZ (an independent and impartial research, testing and consulting company) on testing brickwork’s performance in earthquakes.  A lot was learned from this testing and while some minor changes were recommended as a whole the test proved modern veneer brickwork performed well in earthquakes, comparable to many other more lightweight claddings.

Calls by some politicians to rebuild Christchurch using only timber have been dismissed by members of the building industry.  The sad reality is that many of Christchurch’s historic and iconic buildings are going to be demolished but hope should not be lost, the city does not need to lose its character. These buildings can be rebuilt using brick to have an authentic look and feel but have the structural integrity vastly improved and brought into line with current New Zealand Building Standards. 

“Austral Bricks brought ‘Brick Art’ to Christchurch to send a positive message about rebuilding, now the mural stands amongst the rubble of the central city when the message is needed more than ever,” concluded Bernard.

AustralBricks email March 2011

Of all the damage to commercial buildings in Christchurch, most was to unreinforced masonry (Urm) building stock with a number of common failure patterns.

Dunedin has a reasonably large number of unreinforced masonry buildings of the type that failed in Canterbury, including commercial buildings and pre-1930 residential properties.

Few Urm buildings were constructed in New Zealand following the Hawkes Bay earthquake in 1931 but there are still about 3750 Urm buildings countrywide with distribution generally in line with the relative prosperity of communities between 1880 and 1930.

So, most of our Urm buildings are more than 80 years old and, while they may be seismically at risk, they make up a significant component of our heritage and landmark buildings, often in key commercial centres.

Following the 1931 earthquake, the New Zealand Standards Institute was established, resulting in the development and updating of building codes.

Ultimately, attention turned to how existing buildings would perform in earthquakes.

Some councils took a more active approach - in Wellington, 500 of the 700 buildings identified as earthquake prone were strengthened or demolished.

Other centres, including Christchurch, took a more passive stance, waiting for a change in use or other development to trigger requirements.

The introduction of the Building Act 2004 required all Territorial Authorities to adopt a policy on earthquake-prone buildings by March 31, 2006.

Jason Ingham, is an associate professor in the department of civil engineering at the University of Auckland and member of the New Zealand Society for Earthquake Engineering management committee.