Engineering geological investigation of the July 2020 Richardson Avenue landslide, Gisborne

Show simple item record

dc.contributor.advisor Brook, Martin
dc.contributor.author Alama, David Jovie
dc.date.accessioned 2021-12-16T22:42:45Z
dc.date.available 2021-12-16T22:42:45Z
dc.date.issued 2021 en
dc.identifier.uri https://hdl.handle.net/2292/57828
dc.description Full Text is available to authenticated members of The University of Auckland only. en
dc.description.abstract On Monday, July 20 2020, a portion of the 35 Richardson Ave, Gisborne property disappeared downhill. A preliminary investigation lead by Dr Murry Cave of the Gisborne Regional Council soon after laid the groundwork for this engineering geological investigation into the 35 Richardson Ave landslide. Field images from the preliminary investigation showed a 1 m tall headscarp, with minor scarps, tension cracks, and ponded surface water across the hillslope. A one-day field investigation was then conducted in preparation of this thesis. This field investigation, coupled with subsurface investigations, and laboratory analysis on soil samples taken from the landslide showed properties and indices not too dissimilar to another landslide in Gisborne, the Wallis Road landslide. The landslide is divided into two sections, an upper area of a clay/silt compound slide with a distinct translational slide. The second section is a channelized sensitive clay flowslide. Ground penetrating radar reveals a possible failure plane c. 6 m for the transitional slide. A multitude of field investigative techniques allowed for the classification of the slope forming material as a well as identifying soil indices such as Atterberg limits, particle size distribution, and clay microstructure. Of particular note is a layer of pumiceous sand, enveloped by clay which was found in one borehole at 1.5 m depth. Such lithology had unique soil indices, such as high sensitivity and it’s the in-situ moisture content moisture content was higher than its liquid limit. These properties can result in its behaviour under disturbance being slurry-like. Similarities of the lithologies found here and within the Wallis Road landslide identifies the sampled soil present at 35 Richardson Ave as belonging to the Mangatuna Formation. Literature surrounding the Mangatuna Formation explains much of the encountered soil properties, from the presence of flocculated smectite seen within SEM imagery, to the high sensitivity, to the particle size distribution. These similarities reveal the history of the formation of the Mangatuna Formation which is proposed to have influenced slope instability with relation to rainwater, tree clearing, and seismicity.
dc.publisher ResearchSpace@Auckland en
dc.relation.ispartof Masters Thesis - University of Auckland en
dc.relation.isreferencedby UoA en
dc.rights Restricted Item. Full Text is available to authenticated members of The University of Auckland only. en
dc.rights Items in ResearchSpace are protected by copyright, with all rights reserved, unless otherwise indicated.
dc.rights.uri https://researchspace.auckland.ac.nz/docs/uoa-docs/rights.htm en
dc.rights.uri http://creativecommons.org/licenses/by-nc-sa/3.0/nz/
dc.title Engineering geological investigation of the July 2020 Richardson Avenue landslide, Gisborne
dc.type Thesis en
thesis.degree.discipline Geology
thesis.degree.grantor The University of Auckland en
thesis.degree.level Masters en
dc.date.updated 2021-11-29T14:45:12Z
dc.rights.holder Copyright: the author en


Files in this item

Find Full text

This item appears in the following Collection(s)

Show simple item record

Share

Search ResearchSpace


Browse

Statistics