Diaphragm feasibly for CMU building

[oengineer]

I have a building that is 58' x 31', composed of CMU walls with a 1 1/2" Type B 20 MTL roof deck. I have been asked to verify the Diaphragm feasibly for the building. I am new to the structural building design. I found a design example to determine the analysis of the wind load on the building to determine the lateral force in kips per wall & I know that the aspect ratio for CMU wall shall be 1.0 or less.

My main question is how to actually verify that strength of the CMU wall is sufficient for the loads acting on the wall. The wall height is 14'-0".The load I am using is 300 plf.

Any suggestions/comments are appreciated.

 

[jayrod12]

Diaphragm feasibility is not about the CMU walls in my mind. It's whether the metal deck diaphragm is strong enough, and stiff enough, to move the loads to the shearwalls without failure (either straight up diaphragm strength failure or excessive deflection). Also ensuring that there is enough of a connection from the deck to the shear walls and the diaphragm chords to allow the appropriate transfer of loads.

 

[SteelPE]

I just dig out my Vulcraft catalog or my SDI manual and check the capacity of the diaphragm against the demand. They have diaphragm table based upon decking:

span
profile (A B or F)
thickness (22 ga 20 ga etc)
attachment pattern to support (3/64, 36/7 etc)
sidelap fasteners
type of attachment to support (welded, screws etc)
type of sidelap fasteners (welded, screws

If you have this information you can easily calculate the capacity of the existing diaphragm. You can even calculate the anticipated deflection of the diaphragm under the applied load