A severe 6.3 magnitude earthquake struck Christchurch, New Zealand’s second-most populous city, on 22 February 2011. Striking at 12:51pm on a busy work day, its epicentre just 10 km south-east of the Christchurch city centre and with a depth of less than 5 km, the earthquake caused widespread damage and multiple fatalities.
The power of the quake caused major damage to buildings across the city. Heritage masonry and modern buildings alike were violently shaken. The spire of the city’s landmark Christchurch Cathedral was reduced to rubble while many of the city’s commercial buildings caved in and crumbled into piles of twisted debris. Direct economic losses from the earthquake amount to approximately NZ$20 billion.
Understanding Seismic Hazards
The ability to make observations rapidly and precisely following a disaster is widely recognised as critical to effective emergency response management. In the short term it helps minimise further structural damage and loss of life. While in the longer term it improves the understanding of seismic hazards which leads to better risk assessment and in turn, the revision of building codes.
To assist with critical earthquake reconnaissance activities, Arup lent support to the Earthquake Engineering Reconnaissance Institute (EERI) Reconnaissance mission.
Comprised of structural engineers, geotechnical engineers, geologists, and disaster social scientists, the mission team provided immediate assessment activities to assist in the emergency response.
The assessment focussed largely on building structures. This included examining the wide ranging liquefaction which affected much of the city centre as well as residential addresses in the eastern suburbs; the performance of building foundations and comparing low-rise residential buildings with multi-story commercial buildings with shallow foundations; as well as observing the damage to heritage masonry structures compared to modern engineered buildings.
Building Expertise in Earthquake Engineering
The collaboration with EERI further strengthens Arup’s skills and broadens its expertise in earthquake engineering. Limiting the seismic risk and understanding the behaviour buildings and geo-structures when subjected to earthquake forces is critical to construction practices in earthquake zones.
Arup seismic specialist Tim Mote and geotechnical engineer James Dismuke were part of the EERI task force. Tim comments: “Participating in earthquake reconnaissance is a vivid reminder of why we are actively engaged in earthquake engineering and risk management. This mission reinforces our organisation’s commitment to providing highly skilled technical expertise in situations of disaster management and recovery. And although earthquakes are unavoidable, large-scale disasters can be prevented with effective building construction codes.
Together Tim and James contributed critical skills to EERI’s mission and provided effective emergency management activities. Our partnership with EERI demonstrates Arup’s commitment to active engagement in earthquake engineering and risk management.
Our partnership with EERI demonstrates Arup’s commitment to active engagement in earthquake engineering and risk management.