additional moments in slender columns

[lbarker]

When checking reinforced concrete columns for an existing structure, is it acceptable to use the actual deflection of the column as given from the finite element model to calculate the additional moment due to the slenderness of the column?

I am modelling a concrete jetty structure in STAAD. If I use the deflection of the column given in BS8110 to calculate the additional moment then the piles fail. If I use the deflection of the column that comes out of the model then the piles are ok.

The structure is existing - there is no evidence of structural failure of the columns, and I am loathe to have to suggest that extensive strengthening work is carried out to the columns if it is not necessary in reality.

 

[swearingen]

Short answer - no.

The code is there for a reason. You're going to have to figure out a way to strengthen it or justify why the code does not apply to you. "But the model said I could ignore the code" will probably not hold up in a court of law...


If you "heard" it on the internet, it's guilty until proven innocent. - DCS

http://www.eng-tips.com/supportus.cfm

 

[271828]

LOL, ACI needs to develop a Direct Analysis Method for concrete columns!!

It's been 4 years since I saw an ACI Code. Is there not an "out" in there somewhere that lets one use measured or known properties or "rational analysis" instead of the typical Code equations? If not, then there needs to be!