International Symposium on Mitigative Measures against Snow ...

<strong>International</strong> <strong>Symposium</strong> on Mitigative Measures against Snow Avalanches
Egilsstaðir, Iceland, March 11–14, 2008
Avalanche protections in Iceland designed by VST Consulting
Engineers Ltd.: Experience and examples
Hallgrímur Daði Indriðason 1 *, Flosi Sigurðsson 1 , Gunnar Guðni Tómasson 2 and Kristín
Martha Hákonardóttir 1
1 VST Consulting Engineers Ltd., Ármúli 4, IS-108 Reykjavík, ICELAND
2 Reykjavik University Iceland, Kringlan 1, IS-103 Reykjavík, ICELAND
*Corresponding author, e-mail: hallgrimur.d.indridason (at) vst.is
ABSTRACT
VST Consulting Engineers Ltd. have been involved in the development and design of
avalanche protection work around Iceland since 1990. Methodology and design criteria,
including legislative framework have evolved considerably during the period, mainly due to
enormous increase in safety requirements after the destructive avalanches in Súðavík and
Flateyri in 1995. Extensive research on avalanches and protection measures and acquired
experience of structural design and constructions of avalanche defences has also lead to
improvements.
VST have carried out appraisal studies for avalanche protections at close to fifteen sites
around Iceland, occasionally in cooperation with other consultants and specialists. The
studies have included the design of deflecting dams, catching dams, braking mounds and
steep splitters in the runout zones and supporting structures in the starting zones.
Most of the protection proposals involve the design of dams. Deflecting dams have generally
been designed as earth fill dams and catching dams are also designed as earth fill dams with a
steep front facing the avalanche constructed with earth reinforcement systems.
The first major avalanche protection project in Iceland was undertaken by VST in Flateyri,
northwest Iceland, designed in 1996. The protective structures consist of two deflecting
dams, located directly above the village that form a wedge shaped structure in the hillside,
with a small catching dam extending between the two deflecting dams in the lowermost part
of the area.
1. INTRODUCTION
VST Consulting Engineers Ltd. have been involved in the development and design of
avalanche protection work around Iceland since 1990. The work includes hazard assessments,
appraisal studies, technical design, preparation of tender documents, supervision during
construction and general consulting on technical issues. More than 20 separate projects of
various proportions have been completed during this period.
Methodology and design criteria, including legislative framework have evolved considerably
for the past 15−20 years, mainly due to enormous increase in safety requirements after the
destructive avalanches in Súðavík and Flateyri in 1995. The legislative framework consists of
an act on protective measures against avalanches and landslides (Icelandic Ministry for the
Environment, 1997a), a regulation with the same title (Icelandic Ministry for the Environment,
1997b) and a regulation on hazard zoning due to snow- and landslides, classification
124 Avalanche protections in Iceland designed by VST Consulting Engineers Ltd.