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[Antico]

Hello everyone,


I'm investigating design methods of r.c frames using simple and rigid connections using BS 8110-1: 1997. Clause 3.2.1.2.4 basically states that a beam can be analysed by considering it as a continuous beam over pinned supports ignoring moment transfer to the columns.
Logically, I would assume that only nominal moment transfer would occur to the columns.

However, Clause 3.2.1.2.5 goes on to say that moments can be calculated using moment distribution on asymmetrically-loaded columns(Edge columns) in simplified beams analysis.

Upon carrying out some calculations I find that the bending moment generated in the column is pretty much the same as that when carrying out a frame analysis.
That for me is counter intuitive for the following,

Simplified beam analysis makes no provision for rotational restraint at the support, hence the design moments will be greater than for a frame analysis. More reinforcement will be provided and thus yielding a stiffer section.
How can edge moment transfer of the beam to the column possibly be the same for both simplified and frame analysis?

I would be very grateful for any clarifications and guidance you guys can offer.