Dr. Liam Wotherspoon – Site Characterisation in New Zealand

Site Characterisation in New Zealand: Latest research and best practice

Dr. Liam Wotherspoon

(Senior Lecturer, University of Auckland)

Auckland PresentationTuesday 25 July 2017

Christchurch PresentationMonday 10 July 2017

Wellington PresentationTuesday 11 July 2017

Video recording link:

Recent earthquakes in New Zealand have clearly highlighted the influence of site effects on the seismic demands experienced by the built environment. An extensive database of ground motion records has also been captured by the strong motion station (SMS) network across New Zealand from these events. However in order to comprehensively understand the ground motions recorded at these sites and to be able to relate these motions to other locations, a detailed understanding of the profile at each SMS is needed. This knowledge can then be used to inform the development of future design practice to better capture these effects. Best practice implementation and interpretation of geophysical investigation methods is a key input into site characterisation.

Methods that are currently utilised for site classification in New Zealand will be discussed, including sCPT, sDMT and surface wave based methods. Particular attention will be given to some of the interpretation issues for each method and approaches to mitigate these issues. The main body of the presentation will then focus on the regional site characterisation studies that have been recently completed or are currently underway across the country. Geotechnical and geophysical investigation methods will be presented, along with the importance of background knowledge of the underlying geology of a site/region. Investigations will be related back to seismic design and how the site characteristics fit within the NZS117.5 site subsoil classification framework.


Liam Wotherspoon is a Senior Lecturer in the Department of Civil and Environmental Engineering at the University of Auckland. His research focuses on a range of structural and geotechnical aspects of earthquake engineering, including site characterisation, large scale field testing and soil-foundation-structure interaction. He sits on the leadership teams of QuakeCoRE and the Resilience to Nature’s Challenges research programmes, and is a Management Committee member for the New Zealand Society for Earthquake Engineering. He was awarded the EQC/NZSEE Ivan Skinner Award in 2015, with a focus on improving dynamic site characterisation across New Zealand