UPH Learns How to Manage Earthquake from New Zealand?s Engineers

The Canterbury earthquake first happened on September 7, 2012. The 7.1 magnitude quake caused major damage and destruction to URM. The quake happened again on December 23, 2010 (M4.8), February 22, 2011 (M6.3), and June 13, 2011 (M6.0). With unprecedented sequence, the quake cause extensive liquefaction and soil spreading. The 2010 September caused damage to mostly unreinforced masonry (URM) buildings and minor damage to reinforced concrete (RC) buildings. The February earthquake caused extensive damage/destruction and human loss, high horizontal and vertical acceleration.

Bothara noted that RC buildings performed very well during the earthquake. Some of the materials that he noted have performed very well during the earthquake include plastic hinge, shear walls, and eccentrically braced frame. He observed that bands protect the buildings from major damage and base isolation, for instance in Christchurch Women?s Hospital, also make the building safe. Nonetheless, parapet walls are extremely hazardous and could kill people.

Bothara mentioned a few lessons taken from the earthquake. Design seismic loads/spectra are only a small parameter for introducing resilience to any building. Good configuration clearly defined load paths important for earthquake resilience. URM buildings suffered the most damage/destruction though strengthened one performed well. In addition, post-1976 buildings performed well. Building configuration (both vertical and horizontal) and ductile detailing played a major role in survival of buildings, he said.

Wijanto also noted a few lessons from the catastrophe. It is important to the community who occupy buildings for the authorities to maintain an effective Building Code enforcement and audit process, including the keeping of publicly transparent compliance records. Good seismic resisting structures require good design, good materials, and good construction. There is also an urgent need for ongoing continuing professional development and education for designers, construction engineers and building code enforcement officials, to develop and maintain their technical competency. In addition, there is an urgent need to develop a guide for conducting post-earthquake structural assessment and repairs, including a quick way to identify appropriate repair strategies. It is important to urgently implement effective and cooperative emergency response schemes involving all relevant agencies. Seismic drills for response agencies need to occur regularly. (dee)

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