SPColumn - ACI318 Second order Analysis ..
SPColumn - ACI318 Second order Analysis ..
(OP)
Good morning guys,
I was checking a column versus buckling using SPColumn software and following ACI318 chapter 10 recomendations for moment magnification procedure .. After the analysis on SPColumn, i have received a message stating the following "Magnified (second-order) moment exceeds 1.4 times first-order moment. Revise column!" .. This is stated in chapter 10.10.2.1 ..
What is the solution of such situation ?
To check this column, i have extracted the forces applied to this column after doing a PDelta analysis in Etabs;
Could this condition be neglected if a non-linear PDelta analysis is done ?
Thank you ..
I was checking a column versus buckling using SPColumn software and following ACI318 chapter 10 recomendations for moment magnification procedure .. After the analysis on SPColumn, i have received a message stating the following "Magnified (second-order) moment exceeds 1.4 times first-order moment. Revise column!" .. This is stated in chapter 10.10.2.1 ..
What is the solution of such situation ?
To check this column, i have extracted the forces applied to this column after doing a PDelta analysis in Etabs;
Could this condition be neglected if a non-linear PDelta analysis is done ?
Thank you ..





RE: SPColumn - ACI318 Second order Analysis ..
I wouldn't say neglected but, most likely, remedied. I'm guessing that your KL value is too high and you've got SPColumn magnifying big P-delta moments that you've already magnified in ETABS.
What's your floor to floor height?
What are you and SPColumn using for KL?
Are the columns part of a moment frame system or do they just ride along with your shear walls?
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: SPColumn - ACI318 Second order Analysis ..
Well the KL values is equal to 1*6.6 m (quite high) and the lateral resisting system is a shear walls system not frame system ..
RE: SPColumn - ACI318 Second order Analysis ..
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: SPColumn - ACI318 Second order Analysis ..
My point is that am i magnifiying twice the moment, once in etabs and twice in SPcolumn ?
RE: SPColumn - ACI318 Second order Analysis ..
It's interesting to note that the commentary to the ACI section that you referenced only mentions P-Big-Delta effects, even though the clause itself just references general second order effects.
Since this is a non-sway column, can you justify a K value less than one?
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: SPColumn - ACI318 Second order Analysis ..
RE: SPColumn - ACI318 Second order Analysis ..
RE: SPColumn - ACI318 Second order Analysis ..