Moment Frame to Slab Connection
Moment Frame to Slab Connection
(OP)
For a 2 column 1 beam moment frame designed as pinned at the slab-on-grade (w/ monolithic edge beam) foundation, I assume there will be some moment transferred to the slab.
Is there a prescibed method to determine the amount of moment to resist, or just design for the cracking moment?
Thanks for any help.
Is there a prescibed method to determine the amount of moment to resist, or just design for the cracking moment?
Thanks for any help.






RE: Moment Frame to Slab Connection
You can do 2-D modeling on STAAD and play the fixity of the base and see how much moment you can live with for a given column size and base plate detail.
The pre-engineered metal building designers and suppliers use these types of frames to resist lateral loads in lieu of X-bracing. They normally do not attach the bent/frame to the foundations. Instead, they terminate the bent column few inches above the slab. Thereby, all of the column reactions are transmitted through the rigid frame column base.
I hope this helps
RE: Moment Frame to Slab Connection
I appreciate your response.
It is a pre-engineered metal bldg. The plans indicate the structural steel columns have base plates welded to the columns and are bolted to the foundation slab (slab designed by others - me) using 4 bolts.
I could analyze the frame, but that would involve considerable time to model the structure (members are not prismatic) and reproduce the wind loads, etc.
I am considering analyzing the base area of the column to determine the moment capacity, and then designing that area of the slab to resist that moment.
Any other suggestions or comments are appreciated. Thanks.
RE: Moment Frame to Slab Connection
Hairpins are usually used to resist the horizontal component of the frames.
It has been my experience that they will design the frames as pinned conditions. The building designer will also supply you with the anchor bolt design. All you have to do is design the foundations to resist the reactions. Watch out for the following:
1. The reactions and their combinations
2. X-bracing reactions
3. Bent/moment frame, if used, to resist lateral wind loads
4. Any other conditions that are peculiar to the PEMB building and the site.
Good luck