Christchurch Earthquake - An Overview (pdf, 1MB)

Why buildings respond differently to earthquakes (pdf, 155KB)

BMC Christchurch Office

Our thoughts are always with the residents of Christchurch after the destructive 6.3 magnitude earthquake which hit the city at 12:51 on Tuesday 22 February 2011.

The BMC team responded immediately to the call from the Institution of Professional Engineers for volunteer structural engineers to help with the assessment of buildings in the CBD. Since that day we have been providing support and are committed to assisting with the re-build.

In April 2011 BMC established a Christchurch Office which has grown to become a unique collaboration between six colleague engineering companies, five from the North Island. The companies all provide highly experienced CPEng engineers who travel to Christchurch on a weekly rostered basis and work from our office near Moorhouse Ave. The commaraderie and dedication to the work at hand provides a high powered “think tank”…. with a pool of great experience working together to effect the best solution for our clients. 

The companies working with BMC, all with a common objective to help the people of Christchurch, are:

 ACH Consulting Ltd, Auckland. www.achconsulting.co.nz 

 Peter Alderton, Brett Chick, Nick Houlding

 Aireys Consulting, Auckland  www.aireys.co.nz 
 Ian Gibson, Roger Twiname, Dave McKernzie, Mike Williams, Steve Moon.

 ISP Consulting Engineers Ltd , Wellington  www.isp.co.nz

 Stuart Preston

 Lautrec Technology Group, Auckland  www.lautrec.co.nz

 Kevin Brown

 Marine Technology Consultants, Christchurch

 Peter Phelan

 Sawrey Consulting Engineers, Wellington  www.sawrey.co.nz 

 Stephen Sawrey, Chris Pine 

  IPENZ has issued a Fact Sheet setting out more accurate details of the earthquake and the subsequent impact this has had on the buildings of Christchurch and we encourage you to read the PDF document attached above. There is also a link to the Office of the Prime Minister’s Science Advisory Committee who have published an article which provides detail on the scale of the event and we encourage you to visit that site also.

This was a natural event of global proportions. Peak ground accelerations (PGA) were measured at over 2g (ie 2 times the acceleration of gravity).  The design earthquake return period is 1 in 500 years and the actual earthquake return period for this event is over 1 in 2500 years.

As the epicenter was very close to Christchurch the shaking recorded is some of the most destructive in modern times. In the face of these destructive forces many times greater than the loads the buildings were designed to resist, the vast majority of buildings in Christchurch in general performed exceptionally well. There are, of course, 2 notable exceptions as well as the many unreinforced brick masonry buildings.

While due investigation is required to see what can be done better in the future, it is worth remembering that despite the size of the Christchurch earthquakes destructive force the vast majority of buildings are still standing. Contrary to many media reports this is a clear demonstration that the modern seismic engineering and construction in New Zealand is world class. In general the buildings performed as their design had intended - absorbing huge amounts of energy but remained standing and allowed people to evacuate.

There have also been some media attempts to compare the Sendai (Japan, 11 March) and Christchurch earthquakes. While the Sendai earthquake was a massive magnitude 9 event, the felt effects onshore were less than 25% of that experienced in Christchurch from the magnitude 6.3 earthquake. A multitude of variables need to be considered when assessing the ultimate impact of any earthquake event and comparisons based merely on size are misleading at best.

INTERMEDIATE /SENIOR STRUCTURAL ENGINEER, Lake Wanaka , New Zealand

• · Opportunity to become a Team Leader in a growing company

• · Opportunity to at last get a great work/life balance with an awesome family Lifestyle

• · Opportunity to be part of business development

Batchelar McDougall Consulting (BMC) Ltd is a structural engineering consultancy with offices in Wanaka and Christchurch. We have an opportunity for an Intermediate/Senior Structural Engineer to join the Wanaka team in providing services to the Central Otago region and to assist the Christchurch Team in the re-build of Christchurch. 

The successful applicant will have a relevant tertiary qualification and come from a diverse background with design experience in concrete, steel, masonry and timber. The Wanaka office has a diverse range of challenging small to medium sized projects including engineering design of new residential and commercial buildings including construction monitoring, discovering what caused the failure & destruction of a rotary irrigator, earthquake assessment, design of strengthening works for earthquake prone buildings and designing alpine structures on the ski areas, to name a few.

We would like a person to join our busy team who has initiative, enthusiasm and excels in a team environment. We can offer an excellent work environment with development opportunities. Competitive remuneration and “Powder Days” off are also offered as part of the company’s holistic ethos. Imagine an office view of Lake Wanaka and the mountains …. Skiing on New Zealand’s best ski fields … fishing, boating, or taking part in any of the region’s outdoor activities which are at your doorstep. A rare opportunity to work where you want to live and enjoy a fantastic lifestyle.

Please email your application including a current C.V. to office@bmconsult.co.nz. www.bmconsult.co.nz