International Symposium on Mitigative Measures against Snow ...
International Symposium on Mitigative Measures against Snow ...
International Symposium on Mitigative Measures against Snow ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
<str<strong>on</strong>g>Internati<strong>on</strong>al</str<strong>on</strong>g> <str<strong>on</strong>g>Symposium</str<strong>on</strong>g> <strong>on</strong> <strong>Mitigative</strong> <strong>Measures</strong> <strong>against</strong> <strong>Snow</strong> Avalanches<br />
Egilsstaðir, Iceland, March 11–14, 2008<br />
hasis was put <strong>on</strong> two avalanche paths which were c<strong>on</strong>sidered to be the most destructive <strong>on</strong>es<br />
in that area. Avalanches and mud slides are frequent from those paths and a few avalanches<br />
Figure 3 Avalanche defences in Drangagil, Neskaupstaður. Catching dam with steep fr<strong>on</strong>t<br />
and supporting structures (photos: Hallgrímur D. Indriðas<strong>on</strong>).<br />
have reached the shore (Ytra-Tröllagil in 1894 and Miðstrandarskarð in 1974 causing 7<br />
casualties).<br />
The proposed defence structures in the Tröllagil area are of four types: 1) Supporting structures<br />
located in the starting z<strong>on</strong>es of the two gullies, 3.5−4.5 m high and approximately<br />
1800 m l<strong>on</strong>g. 2) Braking mounds in two rows above the residential area, a total of 23 mounds.<br />
The mounds are designed with a steep fr<strong>on</strong>t facing the mountain. The mounds are 10 m high<br />
and each mound is approximately 10 m wide at the top. 3) A catching dam, 620 m l<strong>on</strong>g at a<br />
distance of approximately 100 m from the houses closest to the dam. It is 16.5−18.5 m high<br />
with a steep fr<strong>on</strong>t facing the mountain. 4) A deflecting dam west of the residential area. The<br />
dam is 390 m l<strong>on</strong>g and 17 m high and is designed with a c<strong>on</strong>venti<strong>on</strong>al slope of the fill<br />
material used.<br />
Figure 4 Proposed avalanche defences in the Tröllagil-area, Neskaupstaður. A catching<br />
dam with steep fr<strong>on</strong>t, braking mounds and a deflecting dam (photo: Hallgrímur D.<br />
Indriðas<strong>on</strong>, computer illustrated).<br />
The total volume of the catching dam, braking mounds and deflecting dam is estimated to be<br />
around 565,000 m 3 . The steep fr<strong>on</strong>ts facing the mountain will be built with an earth<br />
reinforcement system made of steel.<br />
Local residents were in general satisfied with the design of the Drangagil protecti<strong>on</strong> measures<br />
and the defence structures were therefore, where possible, designed with the same appearance.<br />
The proposal has been accepted and c<strong>on</strong>structi<strong>on</strong> is expected to start in 2008.<br />
128 Avalanche protecti<strong>on</strong>s in Iceland designed by VST C<strong>on</strong>sulting Engineers Ltd.
Change language