Sydney Chapter

Liquefaction Hazard in Australia

Tim Mote & James Dismuke

The Canterbury Earthquakes of 2010 and 2011 caused tremendous damage to the City of Christchurch and its surrounding areas. Aspects of the earthquakes are well documented, including the seismology as well as damage to land and structures within the CBD and suburbs. In the two years since the first earthquake occurred in September 2010, a great effort has been made by geotechnical and structural engineering professionals to assess damage and provide engineering input toward rebuilding the City.

Defining residential zones where the risk is considered too high to occupy within an evolving understanding of the seismic hazards and design ground motions have been a challenge faced by the multiple government agencies responsible for rebuilding Christchurch. Engineering for the rebuild is difficult at the present time because the pressure to move forward is faced with uncertainty in the analysis and design approach required to achieve design standards.

This presentation will provide background on the earthquake sequence and ground motions with the type and extent of damage sustained to the City; ongoing efforts for evaluating and classifying damage; the evolution of the current state of design standards in Christchurch; and current geotechnical practice for rebuilding Christchurch. In addition a current understanding of earthquake hazard in Australia, including Geoscience Australia’s draft 2012 Australian Hazard Map, and liquefaction assessments within AS1170.4 will be presented.

Engineers Australia members participating in AGS technical sessions can record attendance on their personal CPD logs. Members should refer to Engineers Australia CPD policy for details on CPD types, requirements and auditing guidelines.