NZSEE/AEES Learning from Earthquakes Mission to Chile

A magnitude 8.8 earthquake occurred offshore Maule, Chile on Saturday, February  27, 2010 at 3:34am local time. The earthquake generated a destructive tsunami and landslides that between them caused the deaths of almost 500 people and the destruction of 200,000 buildings.

At the NZSEE annual conference in Wellington in late March, NZSEE and AEES committee members discussed sending a joint mission to Chile under the learning from earthquakes banner.  The purpose of the mission is to gather data on the earthquake and on the earthquake resistant performance of systems, buildings and infrastructure. The lessons to be learnt range over a wide spectrum from actual earthquake loading levels compared with design levels, building structure performance and planning to governance/legislative initiatives.

Subsequently fourteen members from New Zealand, and one Australian (engineering seismologist Gary Gibson from ES&S) agreed to join the team led by Hugh Cowan and Peter Smith. Gary is the IAEE representative for AEES and has been to Chile on several occasions. NZSEE has done all the organising for the trip. The hosts of the mission are the University of Chile (UC) and the Pontifical University of Chile (PUC). Two of the mission are Chilean doctoral candidates in NZ, one of them jointly supervised by Prof Mike Griffith in Adelaide.

Building performance is a particular interest; buildings constructed or retrofitted since the mid-1970s that have been designed to a similar philosophy and standard to those in New Zealand and many SW Pacific countries that have adopted a New Zealand code.  Essentially we need to know if the design/construction details provide an acceptable level of performance to protect the building and its function.

Significant investigations have already taken place by Chilean organisations and external teams.  Additional investigations will:

1. Obtain information on the ground motion, on foundation materials, and on the dynamic interaction of buildings and foundations.
2. Choose appropriate buildings, damaged and undamaged, and obtain as much information as possible on the design details and materials of construction, likewise for special structures such as schools and hospitals, dams and pipelines.
3. Obtain information on the loadings and materials standards used in the design.
4. Investigate the interaction of buildings to determine whether pounding was an issue and how the flooring systems performed.
5. Residential buildings will be examined including light timber framed houses.
6. Examine the performance of non-structural elements within buildings, including facades, partitions and suspended ceilings.
7. Noting that liquefaction was extensive in several areas investigate the impact on the stormwater and sewerage system.
8. Collect tsunami information which will be of use to tsunami warning groups throughout the SW Pacific.
9. Discuss proposed changes to regulations because of the experience from the earthquake, to emergency management, environmental protection, public health issues, etc

Some of the party left for Chile on 23 April, the rest depart on 01 May and will be away for approximately 15 days. NZSEE and AEES are paying the trip costs whilst members’ time is being generously donated by their employers.

Gary Gibson will be sending updates throughout the trip. Read the blog here.