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If there are secondary beams running between primary beams, and columns support the primary beams, then is it allowable to have the occasional secondary beam pinned to a column? Otherwise it seems to me that it would be impossible to connect a secondary beam to a primary beam at a location where a column is. For example, in the picture below, it appears as though the third secondary beam from the left is connected directly to the column. In this case, is the primary beam completely unaffected by this beam?

I was taught that if a beam is connected to a column then it is no longer a secondary beam. Moreover, would the analysis of a single primary beam not include the concentrated loads of the secondary beams which connect only to the column? And in practice, do structural engineers often do this?

enter image description here

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  • $\begingroup$ Sorry, I should have elaborated more. I was taught that if a beam is connected to a column then it is no longer a primary beam. Moreover, would the analysis of a single primary beam not include the concentrated loads of the secondary beams which connect only to the column? And in practise, do structural engineers often do this? Thanks. $\endgroup$ – Terence Oct 13 '18 at 12:32
  • $\begingroup$ No longer a secondary beam* $\endgroup$ – Terence Oct 13 '18 at 12:40
  • $\begingroup$ I have added your additional information to the question. In the future, you can edit the question to add information instead of putting it in the comments. $\endgroup$ – hazzey Oct 13 '18 at 13:15
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Primary Versus Secondary

Think about primary and secondary beams less about where they are connected and more about the size or amount of load that they are taking. (These mean the same thing if you think about it.)

A secondary beam only takes load from the deck and a primary beam takes the multiple point loads from the ends of the secondary beams.

When you look at the beams in this manner, the fact that the secondary beam needs to physically connect to a column doesn't change its type.

Connections

Beams are designed for the loads that they are expected to carry. If a member is connected to a column, then it isn't connected to a beam. In this case, there is no need to imagine connections where there aren't any.

The physical constraints of the beam layout means that the end connection of every secondary beam is not the same. In this situation, there would be many typical connections and a few unique connections. This is very common.

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