Opening the Snow/Wind Load dialog and clicking the Wind tab displays the following dialog.
The dialog box is divided into several fields with certain option groups. The following options are provided in the top part of the dialog box:
- Basic wind speed V - Specifies the basic wind speed V
- Wind directionality factor kd - Specifies the wind directionality factor Kd
- When the Topographic factor option is selected, a topographic factor is considered in calculations. When this option is cleared, the value of this factor is 1. The value of the topographic factor is determined by the values of the following parameters: hill shape, Lh, x and H. Selecting the Upwind option changes the calculation of the topographic factor for one type of hill shape: 2-D escarpment.
- In the Gust effect factor G field, you can define a value for the G factor. It is determined by the values of the following parameters: building natural frequency n1 and damping ratio b. If the Manual option is selected, a field becomes accessible where you can specify the value for the G factor.
The Use alternative method for low-rise buildings, when applicable option is at the bottom of the dialog. The alternative method applies to buildings with heights up to 60 feet. For this alternative method, wind factors are calculated based on the diagram in figure 6-4. For the standard method, wind factors are calculated based on the diagram in figure6-3.
When the Use alternative method for low-rise buildings, when applicable is selected, buildings whose height is less than or equal to 60 feet have their wind factors calculated according to figure 6-4 in the ASCE 7-16 code. If this option is cleared, then for every structure, including those whose height is less than or equal to 60 feet, the calculations are performed based on the diagram in figure 6-3.
Clicking Coefficient opens the dialog for specifying the coefficients for a wind load.