| dc.creator | Dellow, G. D. | |
| dc.creator | Read, S. A. L. | |
| dc.creator | Begg, J. G. | |
| dc.creator | Van Dissen, R. J. | |
| dc.creator | Perrin, N. D. | |
| dc.date | 1992-12-31 | |
| dc.identifier | https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/696 | |
| dc.identifier | 10.5459/bnzsee.25.4.332-344 | |
| dc.description | Geological materials in the Lower Hutt, Eastbourne, Wainuiomata, and Porirua urban areas are mapped and described as part of a multi-disciplinary assessment of seismic ground shaking hazards. Emphasis is mainly on the flat-lying parts of these areas which are underlain by variable Quaternary-age sediments that overlie Permian-Mesozoic age 'greywacke' bedrock. Within the Quaternary-age sediments, the two material types recognised on strength characteristics are:
1) Soft sediments, typically composed of normally consolidated, fine-grained materials (sand, silt and clay), with typical standard penetration values (SPT) of <20 blows/300 mm; and
2) Loose to compact coarser-grained materials (sand, gravel), with SPT values of >20 blows/300 mm.
The total thickness and nature of Quaternary-age sediments in the study areas is described, with particular emphasis on the thickness and geotechnical properties of near-surface sediments. Such sediments are considered likely to have a significant influence on the an1plification and attenuation of ground shaking intensity during earthquakes.
In the Lower Hutt valley, near-surface soft sediments greater than 10 m thick have an areal extent of -16 km2. Such soft sediments underlie much of Petone and the Lower Hutt urban and city centres, and have a maximum known thickness of 27 m near the western end of the Petone foreshore. In the Wainuiomata area, near-surface soft sediments greater than 10 m thick have an areal extent of - 3 km2, and attain a maximum thickness of 32 m. In Porirua, near-surface soft sediments have a maximum thickness of 14 m, cover an area of -2km2, and underlie much of the city centre. In the Lower Hutt valley the total known thickness of Quaternary-age sediments, including near-surface soft sediments is 300 m. Quaternary-age sediments are very much thinner in other areas, with thicknesses of 60 m recorded in Wainuiomata, 10 m in Eastbourne, and 90 m in the Porirua area. | en-US |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | New Zealand Society for Earthquake Engineering | en-US |
| dc.relation | https://bulletin.nzsee.org.nz/index.php/bnzsee/article/view/696/671 | |
| dc.rights | Copyright (c) 1992 G. D. Dellow, S. A. L. Read, J. G. Begg, R. J. Van Dissen, N. D. Perrin | en-US |
| dc.rights | https://creativecommons.org/licenses/by/4.0 | en-US |
| dc.source | Bulletin of the New Zealand Society for Earthquake Engineering; Vol 25 No 4 (1992); 332-344 | en-US |
| dc.source | 2324-1543 | |
| dc.source | 1174-9857 | |
| dc.title | Distribution of geological materials in Lower Hutt and Porirua, New Zealand | en-US |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | Article | en-US |
