Steel frame with CMU shear walls

[vasilios13]

Hello,
I was wondering if anyone had information on a steel building with simple shear connections with cmu infill shear walls. The architect specified cmu for the enclosures around the stairs and elevator shaft. I am looking to tie this into the structural design. They are centered in the building, so I am thinking of making a reinforced cmu core. Has anyone ever done a design like this? The building is 8 stories and is 50'x50'. What kind of connections are needed between the columns, girders and the cmu?
Thanks

 

[RareBugTX]

I have been thinking about this exact issue before, and haven't got the answer yet. But let me tell you from what I have seen built here in Chicago, they are doing simple shear connections at the exterior steel frame and I assume (because I have had no access to the construction documents) that the center core is just assumed to receive all the shear for lateral loads be it in this case wind the controlling factor.I hope that you get a lot of feedback from your question to rationalize the analysis cause I suspect that a lot of the structural system design criteria in a system like this is just empirical.
Best Regards,

Rarebug

 

[hokie66]

The most common approach would be to use the concrete floor slabs as diaphragms to deliver the lateral loads to the core. It would be possible to provide diagonal bracing in the floor framing and steel connections to the core, but you will already have a concrete floor which is much stiffer and can be cast into the core with minimal effort. In this case, the connections of the floor beams to the core only need to provide for vertical load.

If it desired for constructability to erect the whole steel frame before the walls are built and the floors are cast, erection columns can be used at the core and built into the walls.

 

[prsconsultant]

If you have a simple frame, its contribution towards frame action may not be significant. I would design the CMU core to take all the lateral loads without any infill action. You still need to provide shear connectors between the steel frame and the CMU walls.

 

[abdelmageed]

Dear,,,
This is common steel design practice in multistorey buildings called (structure braced by the RC WALL).The two systems addressed in the design :-1/ Gravity load system- that comprises of the slab and beams that transfer GV loads to columns , known as Gravity Columns as they care only of gravity load reactions.Thus, all columns and beams connections are assumed simple.2/Lateral load resisting system-that is represented by the shear wall that receives the LATERAL loads through the inplane action of the slabs (diphragms).That is the way things are done in common practice.If further self insurance is required, please make a 3-d simple mathematical model ,it helps better understanding of the behaviour.
regards
SAM/ABDELMAGEED

 

[csd72]

This should explain all the theory, although it is based on european codes so exact rules will vary.

http://www.kuleuven.be/bwk/materials/Teaching/master/wg14/t1000.htm