The 1979 Abbotsford Landslide, Dunedin, New Zealand: a retrospective look at its nature and causes |
| |
| Authors: | Graham T Hancox |
| |
| Institution: | (1) GNS Science, P.O. Box 30368, Lower Hutt, New Zealand |
| |
| Abstract: | The Abbotsford Landslide of 8 August 1979 occurred in an urban area of Dunedin, New Zealand, causing much damage to houses
and urban infrastructure. Rapid failure occurred after weeks of preliminary movements, resulting in the formation of a approximately
5 million m3 block slide. It caused the loss of 69 houses, with an overall cost of about NZ $10–13 million. After several months of investigations,
a commission of inquiry found that unfavorable geology (weak clay layers in a 7°-dip slope) was the underlying cause of the
landslide. An old sand quarry at the toe of the slope and a leaking water main above the slide area were found to be man-made
factors that contributed to the failure. Slope stability analysis showed that after sand excavation (approximately 300,000 m3), the water table had to rise 0.3 m less for failure to occur. Because the quarry closed 10 years before the landslide occurred,
it is concluded that a long-term rise in groundwater levels because of the increased rainfall over the previous decade and
leakage from the water main controlled the timing of the failure and, in this sense, are considered to have triggered the
landslide. |
| |
| Keywords: | Abbotsford landslide Block slide Groundwater Causal factors Dunedin New Zealand |
| 本文献已被 SpringerLink 等数据库收录！ |
|
