Add New Snow Definition dialog
Used to define parameters used for generating snow loading on a structure per the ASCE 7-02 code.
Opens when the Snow tool is selected in the Define Load Systems group on the Loading ribbon tab.
The feature is currently implemented for structures with flat or sloping roofs. Snow load generation for members of open lattice structures like electrical transmission towers is currently not part of this facility. Hence, the feature is based on panel areas, not the exposed width of individual members.
As a result, the members for which the snow load is to be generated must be clustered together into Floor Groups. For details on creation of groups, refer to TR.16.1 Listing of Entities by Specifying Groups .
| Setting | Description |
|---|---|
| Type No: | Specify an integer value (1, 2, 3, etc.) which denotes a number by which the snow load type will be identified. Multiple snow load types can be created in the same model. |
| Ground Snow Load | The pressure or, weight per unit area, to be used for the calculation of the design snow load, in current units. Use a negative value to indicate loading acting towards the roof (upwards) as per section 7.2 of the SEI/ASCE 7-02 code. |
| Exposure Factor | Specify the exposure factor as per Table 7-2 of the SEI/ASCE-7-02 code. It is dependent upon the type of exposure of the roof (fully exposed/partially exposed/sheltered) and the terrain category, as defined in section 6.5.6 of the code. |
| Thermal Factor | Specify the thermal factor as per Table 7-3 of the SEI/ASCE-7-02 code. It is dependent upon the thermal condition. |
| Importance Factor | Specify the snow importance factor as per Table 7-4 of the SEI/ASCE-7-02 code. This value depends on the category the structure belongs to, as per section 1.5 and Table 1-1 of the code. |