The temporal and spatial variation of snow pressure on structures

Abstract

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. Geotechnical Journal, 22, 2, pp. 166-71, 1985-05-01 The temporal and spatial variation of snow pressure on structures Measurements of snow creep pressure on an avalanche-defence structure in western Norway are presented. Two different types of measurement methods are described and evaluated. Pressure data from four winters are correlated with the following measured snowpack properties: density, snow depth, snowpack temperature, and snowpack stiffness. The results show that maximum and average pressures are strongly dependent on the product of density and snow depth as well as snowpack stiffness. The highest pressures were observed in spring prior to melting of the snowpack. Canadian

Snow-creep forces on masts

“…The pressures at the wall structure did not show any differences when comparing the data from these winters with data from the other winters with the same snow depth and densities (Larsen and others, 1985).…”

“…The total snow pressure is generally dependent on the snow depth and average snow density. As these factors normally increase throughout the winter, the pressure gradually increases towards a maximum at the time when the snow reaches the 0°C isothermal (Larsen and others, 1985).…”

“…During the winter of 1981, the normal temperature profile remained the same throughout January but in early February the temperature was close to 0°C throughout the whole snow cover (Larsen and others, 1985). The same thing happened in 1989 and 1990.…”

“…As Nature is unpredictable concerning weather and snow conditions, it took years to discover design load situations. For the retaining structure, a clear relationship was discovered between the snow pressure and the “Body force index” (product of snow depth h, density ρ and acceleration due to gravity g )(McClung and others, 1984; Larsen and others, 1985). In the late 1980s and early 1990s, new relationships of interest were found for the single-pole elements that totally changed the previous conceptions; they showed that the pressure on a single-pole element is strongly influenced by the temperature in the snowpack during the winter.…”

Snow creep pressures: Effects of structure boundary conditions and snowpack properties compared with field data

“…The incline at the site is nearly constant (25" ) for a long distance upslope from the structure and the ground surface is fairly smooth rock behind the structure. Previously (Larsen et al, 1985 ) the field measurements were described in detail. Supporting field measurements include a set of indexes for snowpack properties: H (average snowdepth), ?= (average snowpack temperature) and S (average snowpack stiffness).…”