×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Are you an
Engineering professional?
Join Eng-Tips Forums!
• Talk With Other Members
• Be Notified Of Responses
• Keyword Search
Favorite Forums
• Automated Signatures
• Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

#### Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

# ASCE 7-10 - Chapter29, Eq 29.5-1

 Forum Search FAQs Links MVPs

## ASCE 7-10 - Chapter29, Eq 29.5-1

(OP)
Hello, I am new to the forum.

I would like to ask for assistance in understanding how to apply Af in Equation 29.5-1. I am attempting to analyse an existing trussed tower. It is an open tower comprised of pipe columns and angle bracing on all four faces. I feel comfortable calculating force coefficient Cf per Figure 29.5-3. I understand that Cf includes contributions of both front and back faces of the tower so that wind does not need be applied to both windward and leeward faces.

My concern is calculating Af properly. ASCE 7-10 states Af = projected area normal to the wind except where Cf is specified for the actual surface area. What does the ASCE 7 mean by the term "except"? If I calculate Cf, what is the the proper way to determine Af to apply wind load at the top of each panel? I found in a FAQ regarding ASCE 7-02 that the area Af used to calculate wind force per foot of tower height is the solid area of one face divided by the panel height. Does it make sence to calculate Af in that manner and multiply by the panel height to obtain a force to be applied at the top of each panel?

Thank you in advance.

### RE: ASCE 7-10 - Chapter29, Eq 29.5-1

I think the "except" that you reference is indicated by Figure 29.5-2: Note 2 and Figure 29.5-3: Note 1. To me it seems to imply you are not allowed to take a reduction in the surface area for "Solid" walls and Signs with openings less than 30% of the gross area. The way you (and the FAQ) suggest seems to appropriately account for the solid area provided that is your load path.

#### Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

#### Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

#### Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!

Close Box

# Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

• Talk To Other Members
• Notification Of Responses To Questions
• Favorite Forums One Click Access
• Keyword Search Of All Posts, And More...

Register now while it's still free!