Using the SkyCiv Load Generator in EN 1991-1-3 Snow Load Calculations

To calculate the snow load pressures for a structure using SkyCiv Load Generator, the process is to define first the code reference. However, only users with a Professional Account or who purchased the standalone Load Generator module will be able to use this calculation. You can purchase the standalone module thru this link.

Purchase the Standalone Load Generator Module

Figure 1. SkyCiv Load Generator UI.

Site Data

Using EN 1991-1-3, you need to an address in the Project Address input first and the software will automatically get the snow load for that location. Currently, the load generator supports the following countries:

• Belgium
• Denmark
• Finland
• France
• Germany
• Ireland
• Italy
• Luxembourg
• The Netherlands
• Portugal
• Romania
• Sweden
• United Kingdom

The snow load values were obtained using Appendix C of EN 1991-1-3 or each individual National Annex. To display the snow region map, you need to click “View Map Data” and then select “Snow.”

Figure 2. Snow map data of SkyCiv Load Generator.

Figure 3. Site data of SkyCiv Load Generator.

SkyCiv has digitalized the map as per the paperback standard. This means, you can simply enter in the site location and the software will automatically pull the ground snow load based on this input. There is a limit to how many times the ground snow load can be obtained on the free tool.

Try our Free Load Generator

Site Input Parameters for Snow Load Calculation

Project Address – Used for getting the nearest ground snow load based on the location

Once the parameters above are completed, we can now proceed to the Structure Data section.

Structure Data

Next step is to define first the Structure you are analyzing. Currently, only Building structure is supported in EN 1991.

Figure 4. Structure data input for buildings.

Structure Input Parameters for Snow Load Calculation

Roof Profile – Used in pressure coefficient values based on the selected roof profile and roof pitch angle
Building Length – the dimension parallel to the wind direction as defined in EN 1991-1-4.
Building Width –  the dimension perpendicular to the wind direction as defined in EN 1991-1-4.
Ground to top of roof Height –  the dimension of the structure from ground to the roof apex.
Roof Pitch Angle – the roof slope in degree

Once the parameters above are completed and validated (clicking Confirm Structure Data), we can now proceed to the Snow Load Parameters section.

Snow Data

To proceed with our snow load calculation, we need to check the checkbox first beside the Snow Load button. By default, this is checked when the site snow data has been defined.

Figure 5. Checkbox for Snow Load Data.

Snow Input Parameters

 

Figure 6. Snow Load Input Parameters.

Topography for EN 1991-1-3 Snow Calculation

This parameter is used in getting Exposure Coefficient C_e. The definition of each option is defined in the table below:

Topography	Definition
Windswept	Flat unobstructed areas exposed on all sides without, or little shelter afforded by terrain, higher construction works or trees.
Normal	Areas where there is no significant removal of snow by wind on construction work, because of terrain, other construction works or trees.
Sheltered	Areas in which the construction work being considered is considerably lower than the surrounding terrain or surrounded by high trees and/or surrounded by higher construction works.

Type of Snow

This parameter is used in getting the mean bulk weight density of snow, γ. The definition of each option is defined in the table below:

Type of Snow	Bulk weight density kN/m3
Fresh	1.0
Settled (several hours or days after its fall)	2.0
Old (several weeks or months after its fall)	3.0
Wet	4.0

By default, this parameter is selected to the recommended snow density value based on the National Annexes.

Consider  Special Load Case?

This parameter is a “Yes” or “No” to calculate Snow Load on other roof cases. Upon selecting “No,” the snow load case for the selected roof profile shall only be calculated. On the other hand, upon selecting “Yes,” the snow load for special case table will show.

Drift on projections and obstruction

This case is used to calculate the snow load drift on obstructions above the roof level such as parapet walls, firewalls, chimneys, etc.

Drift on roof abutting to taller construction works

This case is used to calculate the snow load drift on roof abutting to taller construction works.

Results

The snow load results will show the parameters in calculating the snow load as shown below:

 

Figure 18. Snow load parameters used in the calculation and the calculated snow load for the selected roof profile.

 

Figure 19. Drifted snow load results for special roof cases.

Detailed Calculation

The detailed snow load calculations can be accessed only by Professional account users and those who purchased the standalone load generator module. All the parameters and assumptions used in the calculation are displayed on the report to make it transparent to the user. You can download a sample detailed calculation thru the following links:

• EN 1991 Snow Load

Sign Up for Professional Account Today

 

Get the Standalone Load Generator Module