User documentation
This calculation is presented in three layouts – Full, Standard and Brief
Dialogue
National annex selector
Combobox "National Annex" is used for selecting proper annex for calculation of the snow load.
Snow load requires selecion the national annex, because in Standard EN are not defined characteristic values of snow load on the ground.
For explanation of the National annex parameters related to snow load select national annex from the list below.
General properties
General properties are similar to all snow load forms.
Checkbox "Print headline" represent official name for calculation. User can change it by uncheck "Print headline" and check "Print userdefined headline" and write his own headline into appropriate string line.
Checkbox "Undrifted snow" show/hide calculation of the undrifted snow (Case i)
Checkbox "Drifted snow" show/hide calculation of the drifted snow (Case ii and Case iii)
Geometry of the roof
Left side slope of the duopitch roof α1 in degrees
Right side slope of the duopitch roof α2 in degrees
Checkbox "Snow fences or other obstruction or parapet on left side" define, if obstruction exist. If True, coefficient μ1(α1) = 0,8. If False, coefficient μ1(α1) is calculated.
Checkbox "Snow fences or other obstruction or parapet on left side" define, if obstruction exist. If True, coefficient μ1(α2) = 0,8. If False, coefficient μ1(α2) is calculated.
Parameters of the snow load
These parameters are depended on selected National annex.
Exposure coefficient
These parameters are depended on selected National annex.
Thermal coefficient
These parameters are depended on selected National annex.
Calculation
Characteristic value of snow load on the ground and Coefficients
These parts of calculation are described in the annotation for Coefficients for the snow load
Geometry
Left and right slope is drawn here in degrees.
Left and right side shape coefficients are calculated.
| Angle of pitch of roof α |
0° ≤ α ≤ 30° |
30° ≤ α ≤ 60° |
α ≥ 60° |
| μ1 |
0,8 |
0,8•(60 - α)/30 |
0,0 |
Calculation of the snow load
Case (i) - Undrifted snow
Snow loads s1 and s2 are calculated according formula (5.1) in kN/m2
Case (ii) and Case (iii) - Undrifted snow
Shape in these cases depend on selected national annex.
Standard shapes are calculated according formula (5.1) with proper coefficient μi
Explanation of symbols
s1 - Snow load on the left side of the roof [kN/m2]
s2 - Snow load on the right side of the roof [kN/m2]
α1 - Roof slope on the left side of the roof [°]
α2 - Roof slope on the right side of the roof [°]
μ1(α1) - Shape coefficient on the left side of the roof
μ1(α2) - Shape coefficient on the right side of the roof