Special Sessions

DAY 1 - Thursday 25 March 2021


Address from MBIE Chief Engineer Mike Kerr

See Mike's profile here.

Update on Finalisation of the MBIE / NZGS Geotechnical Guidelines

Speakers: Misko Cubrinovski & Mike Stannard

Kindly supported by:

DAY 2 - Friday 26 March 2021


Panel Discussion: Combining geotechnical and structural for the best results for the project

Soil-structure interaction is a complex problem at the intersection of many disciplines. Whether it is assessment of an existing structure or design of a new, the structural and geotechnical aspects cannot be treated separately. We have moved on from the traditional approach of the geotechnical engineer preparing a report and the structural engineer taking it from there. Or have we? The structure, its foundations and the soil are all part of one system. Understanding how they interact is important for any design. Our panel of structural and geotechnical engineers will lead a discussion to explore how our separate disciplines work together and how that is applied in design and soil structure interaction. Progress in the understanding and modelling of this phenomenon leads to improvements in design practices, safer construction, reduction of loss of life and economic losses from earthquakes. Aspirations for more collaborative working and lifting the game in soil structure interaction analyses will be posed. We welcome members of SESOC to join the conference for this session and to add to the lively discussion.

If you are a SESOC member please view your invitation here & RSVP here.

Panelists: Hamish McKenzie (SESOC President, Holmes Consulting),  Alexei Murashev & Dejan Novakov (WSP), Stuart Palmer (Tonkin+Taylor)

Kindly supported by:

Geomechanical characterisation of greywacke rock masses for dynamic slope-stability analysis, Wellington New Zealand

Torlesse greywacke comprises about 19% of New Zealand’s rock mass at/near the surface. Wellington is New Zealand’s capital city and is underlain predominantly by closely jointed greywacke. The region is also seismically active, and the central city is dissected by the Wellington Fault, which could generate a magnitude M7+ earthquake, with an estimated return period of about 800 years. This research has been carried out as part of the multiyear, multidisciplinary Stability of Land In Dynamic Environments (SLIDE) research project, whose goal is to improve the resilience of New Zealand’s buildings and infrastructure through better knowledge of the behaviour of slopes and develop strategies for more robust remediation approaches. To investigate the seismic response of the greywacke slopes we drilled eight boreholes and used full waveform sonic, and optical and acoustic televiewer downhole survey tools to characterise the insitu rock masses. These results – coupled with field mapping and laboratory unconfined and tensile strength testing of cores containing small-scale, short persistence and closely spaced discontinuities – have been used to derive rock-mass strength properties for dynamic slope stability analyses. This paper will discuss the relationships, or not, between the different scales of observation and measurement and their impact on deriving rock mass geomechanical properties at the slope scale.

Speaker: Chris Massey

NZGS soil & rock guidelines

Speakers Ross Roberts