I am just trying to get some opinions on what is done with RAM Structural System and RAM Concrete Column Design. Currently in ACI 318-08 there are three methods for column design. sections 10.10.3, 10.10.4 and 10.10.5, Nonlinear second-order analysis, Elastic second-order analysis and the moment magnifier procedure respectively.
Is there any way to perform an analysis in RAM Structural System that would satisfy section 10.10.3 of ACI 318-08? If so where can I get guidance on how to do this in RAM Structural System?
Is there any way to perform an analysis in RAM Structural System that would staisfy section 10.10.4 of ACI 318-08? If so where can I get guidance on how to do this in RAM Structural System?
It appears that with the column slenderness box checked in the RAM Concrete Analysis criteria, section 10.10.5 of ACI 318-08 is taken into account, however my question regarding this is would it be beneficial to use the gravity forces on lateral columns from RAM Frame with or without P-delta analysis considered?
Any information about where the above information can be obtained would be greatly appreciated.
Thanks,
Scott B.
Great question. Hopefully others will also comment.
ACI 318-08 Section 10.10.3 requires non-linear analysis, with consideration for shrinkage, creep etc. There are a few things involved here that the analysis in RAM Frame can’t account for.
Moving on to the Elastic second-order analysis approach in section 10.10.4, I think there is an argument to be made that our analysis is “close enough” to satisfy this requirement. The RAM Frame analysis certainly can consider P-Delta effects and the member properties can be adjusted to account for cracking. The sticking point is in the p-delta (or small p-delta) effect from column curvature between stories. Currently there is no way to account for the small p-delta effect in Ram Frame thus we always require moment magnification in RAM Concrete Column.
FYI, there is a nice paper on this subject called “Slender Column Design Based on ACI 318-08” available here: continuingeducation.zweigwhite.com/index.php