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Re: Column design

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As I said you have to detail it properly, make sure negligible moment is transferred to the column. You can detail it in such a way that the end of the beam is just bearing on the column. Just think that the end column is just supporting a pre-cast beam. 
 
I can see their argument of using M=wL^2/8 this way. If you have a beam being supported by the column and design the beam as simply supported then the columns will just act as support to beam reactions.
 
If you design the joint to make sure the moment is transferred from beam to column then you should design the column for the moment that is being transferred.  You only use the ACI provisions for concrete frame if you design the beam and column as frame.  In your case you have a concrete frame with beams and interior columns but hinge at the end columns.
 
Moment are not attracted base on the gross area but based on the capacity of the materials as they are being transferred from member to member. Even how big your gross area is if your joint is not designed to transferr the moment then the moment will just goes back to the beam.  That's the basic theory behind moment distribution of frames and continuous beams. That's why as I said at the beginning detailing is the key.
 
ASQuilalaJr., P.E. 
 
 
 
 
In a message dated 12/17/05 2:39:06 P.M. Pacific Standard Time, ashraf.manjappara(--nospam--at)gmail.com writes:
ASQuilala:
I don't agree with your view and your argument is against ACI 318 S.8.8.1. What will happen if we are not designing column for the moment it attracts based on the gross section area?.