pin connection
pin connection
(OP)
I am designing a concrete footing for a steel framing building. The footing cannot resist any moment. I therefore use a pin support. I could not find a pin connection detail from my textbooks or steel manual. The only detail I found is to use 4 bolts at each corner of base plate . Can this detail be used for a pin connection?
Please help.
Please help.






RE: pin connection
DaveAtkins
RE: pin connection
RE: pin connection
I have seen a number of architectural details for exposed joints, where they have used a true pin, a couple of plates with a large, specially designed pin element. If it is that critical you could investigate it. Otherwise stick with the standard four bolt arrangement.
RE: pin connection
RE: pin connection
RE: pin connection
Im not sure how a one bolt base plate works?? This would introduce an eccentric load in the column.
I think the critical word in your post is 'assume'. As designers we often make assumptions to make our life easier but dont actually reflect reality. So if you asssume it to be pinned, its pinned regardless of what it actaully looks like.
The Steel Construction Institute do have method for taking ito account some fixity when designing pinned base portal frames. They allow you to model the base plate using a dummy member which allows some rotation and then begins to take some moment.
RE: pin connection
In Australia, the Australian Institute of Steel Construction shows a one bolt base plates for parallel flange channels. I have also seen it used with small hollow sections. I dont think its use is highly recommended due to its instability during erection - a point you mention in your post. In Australia I have only seen this detail used when there is next to zero or zero uplift force on the column and the base plate detail is really only used to locate the base of the column.
RE: pin connection
The baseplate, holding down bolts and footing have to be designed to resist the moment, shear and axial load.
Unless the moments are only nominal, typical pinned base details will not be sufficient.
On the subject of safe erection as noted by Ussuri; in Victoria (Australia) the new Occupational Health & Safety Act 2004 which imposes an expressed duty on designers of buildings & structures to ensure that OHS risks are identified and controlled will come into effect in July. This may well lead to similar column base bolting requirements (as well as other requirements) as required in the UK.
RE: pin connection
the column is not infinite small.
so when there is an pressure force and a base plate
there is an resisting moment at the base of the column....
RE: pin connection
RE: pin connection
RE: pin connection