Sloping Steel Columns

[Struct-007]

Could anyone please recommend good references about the analysis and design of sloping steel columns with some design examples if possible?

I need to understand the load transfer mechanism and the limits states that should be considered in design.

Thank you.

 

[strucbells]

I think Modern Steel Construction has had a couple of articles about sloping steel columns in the last year or two. Not really super technical content but at least gave an overview of how they were implemented in a couple of projects.

 

[StructuralAddict]

Yes there should be good information there. Are there any books or guidelines?

 

[human909]

What sort of guidance are you after? How do you expect the slope to significantly change analysis?

 

[StructuralAddict]

For example, if the sloped column spans over several floors, then there will be horizontal component of the force transferred to each floor. How should we design such connections? And how do we determine if the slab/deck is sufficient? What are the limit states that we should consider to design sloping steel columns?

 

[hokie66]

Inclined columns function just like vertical columns, except they may have a bit of bending due to self weight. This is especially true of struts in a more or less horizontal plane, like roof bracing. A column which goes through several floors just transmits the force through axially as long as there is no offset.

 

[Agent666]

Depending on your lateral system, sloped columns can start to attract considerable axial loads under wind or seismic loads as they act in a way as very steep diagonal braces essentially.

The design is the same as designing for any other similar force on connections or floor diaphragms. There is nothing special you need to do, just design to your code using the required equations for the loads present. Some thought might need to be given to larger than design level events if your columns do in fact act to brace the structure. Because unlike say a diagonal brace which predominantly carry only lateral loads, your sloping column could carry significant lateral axial loads in addition to the gravity loads. So if a column buckles it is a lot more detrimental than a brace bucklng in compression obviously.

 

[MIStructE_IRE]

Dont forget about the horizontal reactions!!

 

[milkshakelake]

I agree with the other posts. I would add that it will have a longer clip angle which needs to be designed by the shop detailer and signed/sealed. I generally show axial loads on sloped columns so someone smarter than me can take care of the connections.