Snow support structure, the superstructure of which consists of horizontal bars parallel to the contour line
The part of the structure which transmits forces acting on the superstructure or on the net to the foundations
Structure in which the superstructure is made of netting which forms a slack surface against which forces are exerted
The completed element is sunk on site
The base is built on the site of the structure (for example out of concrete)
Part of the frame (not in contact with the ground) on which are fixed the cross-bars (or the bars) of a rake
Part of the frame on which are fixed the cross-bars or-the longitudinal beams
Part of the structure which supports the up right or the longitudinal beam from below
Structure with a superstructure consisting of bars arranged perpendicular to the contour line
Part of the frame either in contact with the ground or buried, against which rest the bars of some types of rake
Surface area which can support snow (surface which is circumscribed by a superstructure or by a net)
Support surface formed by bars
Rigid join between the foundation bases of the upright and the supporting pillar
Elements of the superstructure whether in snow bridges or rakes
The metric ton (t) has been used as the unit of force. In accordance with current SIA norms., the unit of force is not asterisked or otherwise designated (kp or Newton) which might be desirable to differentiate it from the unit of mass.
An apostrophe (') accompanying specifications of force always signifies force per unit length (load per meter).
Forces shown without an apostrophe (') are the resultants for structures of defined length.
Forces designated with capital letters are resultants pertaining to the height of structures. Those with small letters relate to elements of structures or to units of surface area (specific pressure).
Technical terms used to describe avalanches are taken from the classification of avalanches proposed by the Swiss Federal Institute for Snow and Avalanche Research (SFISAR) in 1965.
| Symbol | Unit | Meaning |
| A | m | Lateral spacing between structures (measured horizontally) |
| a | Coefficient for calculating E (depends on the type of snow) | |
| BK | m | Height of superstructure (average size of the support surface measured perpendicular to the contour line) |
| b | m | Effective load-bearing width of the cross-beams of the superstructure |
| Dext | m | Extreme thickness of snow (the largest value of the maximum thickness of snow in a defined area and taken over a long series of years) |
| DK | m | Effective height of superstructure (by analogy to "thickness of snow" average distance between the upper edge of the support surface and the ground, measured perpendicular to the slope) |
| Dmax | m | Maximum thickness of snow (during one winter in a defined place) |
| D | m | Thickness of snow in the common sense (measured perpendicular to the slope) |
| fc | - | Altitude factor (the density of snow and the creep factor depend on the altitude) |
| f L | - | Spacing factor (for determining L) |
| f R | - | Marginal factor (to calculate the marginal extra load) |
| f s | - | Reduction factor for slack superstructures (reduces the component of the pressure of snow parallel to the slope) |
| G' | t/m' | Extra load caused by the setting of a superstructure at an angle greater than the perpendicular to the slope (weight of the prism of snow contained between the support surface and the plane perpendicular to the slope from the base of the superstructure) |
| G'N | t/m' | Component of G', parallel to the slope |
| G'Q | t/m' | Component of G'. perpendicular to the slope |
| Symbol | Unit | Meaning |
| (Hext ) | m | Extreme height of snow (the largest likely value of the maximum annual height of snow in a defined place, absolute maximum over a long series of winters). Height of snow related to the first general example of loading: full snow cover |
| (Hext ) | m | Average of the extreme heights of snow (average of the extreme heights of snow analogous to |
| HK | m | Height of structure (measured vertically) |
| Hmax | m | Maximum height of snow (maximum height of snow during one winter in a defined place) |
| Hmax | m | Average of the maximum heights of snow (average, for an area of ground, of the maximum height of snow ) |
| H | m | Height of snow in the common sense (measured vertically) |
| h | m | Height of snow related to the second general example offloading: dense partial snow cover |
| K | Creep factor (depends on the density of the snow and on | |
| the declivity) | ||
| L | m | Spacing between structures (measured down the line of the |
| slope) | ||
| 1 | m | Effective length of a structure (horizontal length) |
(tri.rec.)1 |
m | Width of the marginal strip (length along which the marginal loads are applied measured parallel to the contour line) |
| lo | m | Width of the frame of a structure (horizontal distance between the two uprights or the supporting pillars) |
| N | Glide factor (takes into account the roughness of the ground and the exposure of the slope) | |
| P' | t/m' | Component perpendicular to the support surface of the load resultant from snow R' |
| PB | t/m' | Load on one cross-beam perpendicular to the support surface (normal pressure) |
| PH | t/m˛ | Pressure of snow perpendicular to the support surface in the first general example of loading |
| Ph | t/m˛ | Pressure of snow perpendicular to the support surface in the second general example of loading |
| Q' | t/m' | Component parallel to the support surface of the load resultant from snow R' |
| qB | t/m' | Load on one cross-beam parallel to the support surface(tangential force) |
| qH | t/m˛ | Specific pressure of snow parallel to the support surface in the first general example of loading |
| qh | t/m˛ | Specific pressure of snow parallel to the support surface in the second general example of loading |
| Symbol | Unit | Meaning |
| qS | t/m' | Transverse force against an articulated supporting pillar (perpendicular to its axis) |
| R' | t/m' | Resultant load of snow in the plane vertical to the line of the slope (composed of the fundamental pressure, marginal extra loads, and the extra load caused by the down-slope inclination of the superstructure) |
| S'N | t/m' | Component of S' parallel to the slope (caused by the braking of snow creep and glide) |
| SQ' | t/m' | Component of S' perpendicular to the slope (due only to the braking of snow creep) |
| S'R | t/m' | Marginal extra load parallel to the slope (additional load acting on the ends of the support surface) |
| SS | t | Lateral force against the structure (parallel to the contour line) |
| Sad | t/m˛ | Admissible shear stress of undisturbed soil at the soleplate of a sealed foundation under extraction force |
| S*ad | t/m˛ | Admissible shear stress of the material used to fill in over a sunken foundation base under extraction force |
| SB | t/m˛ | Breaking shear stress of undisturbed soil at the soleplate of a sealed foundation under extraction force |
| T | t | Resultant force of the anchorage of the frame (upright) to the upper foundation base |
| t | m | Extreme depth of foundation (measured vertically from the lower corner of the foundation base) |
| U | t | Resultant force of the anchorage of the frame (supporting pillar) to the lower foundation base |
