Progressive Collapse Braced Connections 1

[GBMRAO]

Hi all. Firstly Happy holidays and advance Happy New year wishes to you all and the blog.

Question: i have a building with progressive collapse design.
dead load is 50 psf and live load is 40 psf.
i calculated sigma LD steel as 3.8 deformations controlled and for force controlled its 2
by applying these loads to the floor above the affected area of the column removal it magnified the loads coming on the braces. While my brace sizes are good for the load the connections are becoming crazy.
ASCE 41-13 says connections are typically designed for force controlled but table 3-1 of the same manual says connections shall be designed for both deformation and force controlled.
Slide 10 and 9 of the attachment says to design connections for force controlled.
this is a huge difference in loads. Obviously by engineering judgment says to use the deformation controlled loads as they are high for my connections.

 

[GBMRAO]

ANy help from anyone is appreciated.

 

[ukbridge]

Youve given us the loads, why not everything else? Read over it again and ask yourself would you bother giving advice?

Would you ask your boss to give you advice by presenting him only with the above post?
Post a sketch or your analytical model at the least - results would be nice as well.

I also dont think theres a clear question in your post. At the end of the day communication is everything in our profession, whether by drawings, reports, calculations or asking the opinion of other professionals.

 

[GBMRAO]

Dear UKBridge,

i am really sorry. The other attachment did not go through. here is the attachment i have. You are correct. Communication is everything. I apologize.

 

[ukbridge]

All I see is your original post, some excepts from a code and calculations.

I still cant make out what the actual building is either or a question.

You have to remember most folk (at least myself) dont mind wasting 30-1hr every other evening so because we love engineering and helping others. Nobodies going to read through all that guff and help you out here - try again.

F-!

 

[MacGruber22]

ukbridge - calm down. GBMRAO is just asking when does the code required either force or deformation controlled connections.

GBMRAO - I am not familiar with the code requirements of progressive collapse design, but MrHershey may have a place for you to start:

https://www.eng-tips.com/viewthread.cfm?qid=380209

-Mac

 

[GBMRAO]

Thank all. Yes my question was for connection. I was reading all night and found that we have to apply the similar m factors to connection strength.

Sorry others I may not be that good at expressing my question. Thanks for the link. Will follow .

 

[MacGruber22]

Good deal. I am sure I will have to deal with this at some point. At the moment, all of the government jobs with PC requirements are done by someone else in the office.

FEMA references would also be a good place to look. So much in ASCE and other standards are derived from FEMA documents.

-Mac