Rigid diaphragm?
Rigid diaphragm?
(OP)
I'm having trouble determining which of the two options represent a rigid diaphragm (pdf file attached), it is for a two storey house, using confined CMU walls, to me figure #2 is correct but i've seen both types of construction so i'm confused. For a brief explanation on Confined Masonry check www.world-housing.net, i now this system is mostly common in third world countries.






RE: Rigid diaphragm?
RE: Rigid diaphragm?
Never, but never question engineer's judgement
RE: Rigid diaphragm?
Why do you need rigid diaphragm? Why not analyse as semi-rigid?
RE: Rigid diaphragm?
RE: Rigid diaphragm?
With option #2, you can provide a pour stop angle just for the slab depth which is directly bolted to teh wall (or welded to embed plates). This then directly transfers the shear without putting any roll-over load into the joists.
RE: Rigid diaphragm?
RE: Rigid diaphragm?
#2 I can live with as rigid.
Mike McCann
MMC Engineering
RE: Rigid diaphragm?
RE: Rigid diaphragm?
Do you not have cmu walls above in #1 as you do in #2? It seems #2 would be easier to continue up.
RE: Rigid diaphragm?
UcfSE, the building code used in Nicaragua is practically a copy of the Mexican code, the rigid diaphragm definition that appears on the Nicaraguan code, i'm almost 100% sure it's taken from the IBC.
tngolfer, there are CMU above in #1, i will try to take pictures and post them.
RE: Rigid diaphragm?
as per diagram, not enough lateral fixity between the concrete deck and the cold rolled box beam.
RE: Rigid diaphragm?
RE: Rigid diaphragm?
Check your code, you will find the correct dimensions and detailing to define a diaphragm as rigid.
For example, if you give a look at Eurocode 4 - Design of composite steel and concrete structures, you'll find minimum requirements in order to have a rigid diaphragm.
So, if you have the right dimensions for slab elements, both solutions can be considered rigid. But this isn't the only problem, because even if they are rigid, you have to check if the walls can support the actions received; looking at the figure 2 solution, seems you can have roll-over problems. You have to check it.
RE: Rigid diaphragm?