Concrete Column Slenderness Check to ACI 318

When the bottom of the Column is a foundation and user elects to use Col forces from RAM Concept whereby no Concept forces/moments and therefore RSS will use RAM Conc Analysis(for Col bottom forces and those moments are always negative), for a lack of a better source. This "limitation" in exporting reactions from Concept to RAM RSS is noted.

From the above, RAM Concrete will inadvertently check the column slenderness for a single-curvature case lowering the threshold of eqn 6.2.5b but against the natural response of the column i.e. not possible for a single-curvature end moments(See attached sketch) regardless of skip-loading and pattern loading This is also proven when elected to use col forces/moment from RAM Concrete Analysis, a full structure model.

It would then be nice if cases mentioned, the user is warned that no force/moment avail from Concept and hence taken from RAM Concrete Analysis. Even better if the law of nature is applied i.e. double-curvature, for specific case of columns mentioned.