Changing Column Size
Changing Column Size
(OP)
Dear engineer,
I have a query about column design.We designed a 11 storied building.Which a column size is 12''x 36''.Which As=13.2 in²-3.05%.
But my project engineer argue this size,he suggested me to keep column size 15''x 36'' for workmanship.Also from architectural point of view we have to limit it 36''.So we cant decrease the size.Now my question is if we increase column area,is it need to increase steel area? or we can keep it same.If we keep it same As=2.44%.If we increase steel area it is uneconomical.What is your suggestion please??
I have a query about column design.We designed a 11 storied building.Which a column size is 12''x 36''.Which As=13.2 in²-3.05%.
But my project engineer argue this size,he suggested me to keep column size 15''x 36'' for workmanship.Also from architectural point of view we have to limit it 36''.So we cant decrease the size.Now my question is if we increase column area,is it need to increase steel area? or we can keep it same.If we keep it same As=2.44%.If we increase steel area it is uneconomical.What is your suggestion please??
RIFAT






RE: Changing Column Size
RE: Changing Column Size
RE: Changing Column Size
What are the column sizes above and below?
I assume this is a perimeter column.
Dik
RE: Changing Column Size
kipfoot:Thank you for your brilliant suggestion.That means same arrangement,same ties is your suggestion?
dik:Yes brother it is perimeter column.
RIFAT
RE: Changing Column Size
Sounds as though you ought to be fine. In addition to being over 1%. you'll want to ensure that the reinforcement that you do have is distributed in such a way that you still have the moment capacity that you need. That would be pretty hard to screw up, however, if this is a perimeter column with it's long side parallel to the slab edge. Usually, making flexural things deeper has a positive effect. Of course, it also means that your column will also attract more moment than it would have when it was smaller.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Changing Column Size
I meant to suggest that you use a bigger ties for the bigger column. In other words, if you had a tie that was 10" x 34" change it to be a 13" x 34".
RE: Changing Column Size
Thats why I cant decide,whats your suggestion?If I increase the size or not?
RIFAT
RE: Changing Column Size
Try both approaches, and see what works best. When doing long span beams for parkades, it was often best to have the columns with minimum depth to minimise the moment...
Dik
RE: Changing Column Size
I'd go for the size increase and then either:
1) check it for the new moments OR;
2) don't check it if you're able to confidently use your judgment to assess the outcome.
Seeing as you're here asking this question, I suspect that #1 is the right path for you. That, or let your supervisor make the call.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Changing Column Size