×
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.

(OP)
I have a case where I have a large heavily loaded cantilever that is doing some weird things to my structure. I am currently trying to design my foundation and I am having a hard time with the load combinations found in IBC 2009. I have a case where the "anchor" is resisting uplift load from the cantilever. I have other loads on the column (dead, live and snow). Now when it comes time to check the IBC load combinations I was all set to use 0.6D but that is only a combination for Wind and Seismic not for D+L+S. I am probably going to end up using 0.6D but I am just wondering what others would do in this instance?

I agree with your engineering judgement in this case. I would also tend to use 0.6DL.

I believe there are some notes saying that you can use 0.9DL for some of the other load combinations whenever dead load has a stabilizing effect. Then if you apply a 1.5 safety factor (i.e. you use the method from the old code) then you arrive at a de-facto 0.6 DL.

= 0.9*1/1.5 = 0.6

I take the same approach as you, SteelPE. I have even gone so far as to use 0.9DL + 1.4DL for DL for certain cases. For example, when I have a dead load that is causing overturning. I will use 0.9DL for the axial portion (stabilizing effect) and 1.4DL for the overturning portion (destabilizing effect).

Even if it's not an explicit load combination, I want to meet the intent of the combinations. My example may be a bit over the top, but it was a critical condition with an unreinforced concrete member.

#### 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.

#### Resources

Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a partâ€™s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

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!