Snow wizard (ASCE 7)

Summary

You can use the Snow wizard... to define sufficient site information to calculate the snow loadcases.

Location

Ensure the snow loading code is set as ASCE 7.
On the Load tab, click Snow Load > Snow wizard...

Content

Button, command or option

Description

Page 1 - Basic data (ASCE 7 Snow wizard)

The following basic data is required:

Ground snow load

(No default)

Terrain Category

Options are:

B (urban, suburban, wooded) - Default
C (open terrain scattered obstructions),
D (flat unobstructed areas), Above treeline, Alaska no trees

Exposure

Options are:

Fully exposed
Partially exposed

Exposure factor, C_e

C_e is determined from the following table:


	Fully Exposed	Fully Exposed	Sheltered
B	0.9	1	1.2
C	0.9	1	1.1
D	0.8	0.9	1
Above treeline	0.7	0.8	0
Alaska	0.7	0.8	0

Thermal Condition

Option are:

All except below
Structures kept just above freezing
Unheated open air structures
Structures kept below freezing
Continuously heated greenhouses

Thermal factor, C_t

C_t is determined from the following table:


A	1
B	1.1
C	1.2
D	1.3
E	0.85

Risk Category

Option are:

I
II
III
IV

Snow Importance factor, I_s

I_s is determined from the following table:


I	0.8
II	1
III	1.1
IV	1.2

Flat Roof Snow load, , p_f

p_f is determined from the following:

p_f = 0.7 * C_e * C_t * I_s * p_g

Page 2 - Snow loadcases (AISC Snow wizard)

This page is used to specify the loadcases as follows:

Minimum Snow Load

Option are:

Yes
No

Balanced Snow Load

Option are:

Yes
No

Unbalanced Snow Load

Option are:

No
1
2
3
4

You can select between 1 and 4 cases to generate (1 Unbalanced..., 2 Unbalanced, etc.)

Draft Snow Load

Option are:

No
1
2
3
4

You can select between 1 and 4 cases to generate (1 Unbalanced..., 2 Unbalanced, etc.)

Rain on Snow Surcharge

Option are:

Yes
No

Finish

Completes the Snow wizard... and sets up the loadcases based upon the input.