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
Figure 3 Instrumentation of the Trumer snow nets, as example (photo: BFW).
2.2 Design of snow nets
With the measured data on the snow cover in the test site (snow heights, snow density), the
corresponding snow loads and forces applied to the different components of the snow nets can
be calculated. According to the Swiss guidelines the components of the snow pressure on a
net in the middle of a line are:
• Snow pressure parallel to the slope SN : S N = f S ⋅ H K ⋅ N ⋅ f C kN /
m
fS factor considering the reduction of the snow pressure on a flexible supporting structure [ - ]
HK extreme snow height at the side of the structure [m]
N gliding factor [ - ]
fC altitude factor [ - ]
2 [ ]
• Weight of the snow prism, formed by the supporting plane of the net and an imaginary
plane perpendicular to the slope starting at the base of the net.
According to the guidelines the component of the snow pressure perpendicular to the slope
can be disregarded. The resultant snow pressure is considered to be uniformly distributed over
the height of the net. For the calculation of the snow pressure, averaged values of both the
Rainer, Rammer and Wiatr 43