SOG Shear Reinforcing Under Wall 5

[waytsh]

I am hoping someone can point me in the right direcion. I am looking for recommended shear reinforcing details for a slab-on-grade with a heavily loaded wall. Going thicker with the slab is not a practical option at this point and was wondering if there are any references out there that specifically address this situation. I can find lot with suspended slabs but nothing that seems specific to a slab on grade. Is this not a recommended practice? Particularly if the slab needs to remain water tight? I am currntly entertaining the idea of a "U" or "Z" sirrup but the spacing is going to need to be pretty tight.

I appreciate any thoughts you may have.

Thanks,

waytsh

 

[miecz]

Hokie66 is right. Check previous threads on shear friction; you'll see a wide variety of opinion. If I understood correctly, many engineers would use the bottom flexural reinforcing for shear friction, allowing it to do double duty. I'm not in that camp.

Also, strike that remark I made about reinforcing for the shear in excess of the slab capacity (What was I thinking?). Shear friction reinforcing would need to need to provide for the total design shear at the failure plane.

 

[dik]

I tend to think that shear friction works by putting the rebar into tension... and I consider it being additive... AISC for anchor rods also adds the shear force in the rod to the developed tension... I think that if you are using rebar for both the shear friction and tension, you could be looking at a failure...

Dik

 

[waytsh]

I would agree that the tension bars should not be considered for shear friction. To be honest the more I think about it am a little reluctant to use any shear friction in this situation. When you run the numbers it gives a very high shear capacity. If all this shear capacity is really there from shear friction then why isn't this method mentioned as a shear reinforcing option for suspended slabs or even beams? I can understand how a beam will still need some confinement, but using this method you could greatly increase your stirrup spacing. I'm just wondering if it is not mentioned because testing has shown it is not a viable solution or if the code guys just didn't feel like tackling the topic.