Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Flat slabs limited "edge column" moment transfer

Status
Not open for further replies.

SnapSpace

Structural
Oct 11, 2007
53
HR
Hi!
I have a question on this subject.
When calulating this problem by hand, you divide flat slab into 2 strips, one is the column strip and the second is the middle strip.
When calculating negative moments at the "edge column" we had a limitating moment trasfer to column that was expressed as Mt=0,18*b*d^2*fck. This expression limited the slab section of becoming over-reinforced.
Now, if I calculated this using quivalent frame method, I had an option of reducing negative edge moments by not more then 50%, if calculated moments where higher then this, but then I had to increase the postivive momets in the span by the same precentage..
Im now using structural analysis program that uses FEM.
My question is, should I also limit the values of Momet transfer to edge column, and also reduce -moment/increse +momets if necesary or not?
Thank you:)
 
Replies continue below

Recommended for you

There is definately something wrong with the way you have modelled the analysis, the external column moments should definately be less than the internal moments over the columns.

Also, I dont know the specifics of your analysis package, but I am sure that the slab dosnt stop half way across the column as shown. Model the slab edge as a cantilever to get out to the actual slab edge.

You should get advice from a more experienced person in your office. Dont be afraid to ask, we all have to learn.
 
Yes, if that is what it looks like.

Also, have you allowed for cladding loads along the slab edge? I would recommend you take a closer look at this before you finalise your slab design.

Good luck.
 
What an cladding?
Sorry my english is kinnda limited :-(
 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top