concrete walls out of plane - vertical rebar is the only valid risa design result, horizontal is not
concrete walls out of plane - vertical rebar is the only valid risa design result, horizontal is not
(OP)
I am modelling a foundation wall and after talking with RISA, is was confirmed that the concrete wall design
results are only valid for the vertical reinforcement. So I am duplicating the wall and rotating it vertically.
( the risa tech guy was like, "uh, that should work I think" )
Now I can get horizontal and vertical reinforcement. I love risa, but this seems idiotic.
The model reports Mx and My in either orientation, but only designs the wall for Mx.
It also shows horizontal reinforcing in the wall results, but apparently these result are irrelevant.
I have matched my contours with the 90's finite difference charts just to check and everything jives.
So forces, stresses, reactions are correct, but when risa sizes/checks/optimizes the rebar, it's only the vertical.
Has any one else experienced this and figured out a better way to design the wall in risa3d without rotating a copy of it?
thanks
ps I'm not sure if my question regarding Mu = Mx + Mxy was understood either. I was told risa did this, but I'm skeptical.
results are only valid for the vertical reinforcement. So I am duplicating the wall and rotating it vertically.
( the risa tech guy was like, "uh, that should work I think" )
Now I can get horizontal and vertical reinforcement. I love risa, but this seems idiotic.
The model reports Mx and My in either orientation, but only designs the wall for Mx.
It also shows horizontal reinforcing in the wall results, but apparently these result are irrelevant.
I have matched my contours with the 90's finite difference charts just to check and everything jives.
So forces, stresses, reactions are correct, but when risa sizes/checks/optimizes the rebar, it's only the vertical.
Has any one else experienced this and figured out a better way to design the wall in risa3d without rotating a copy of it?
thanks
ps I'm not sure if my question regarding Mu = Mx + Mxy was understood either. I was told risa did this, but I'm skeptical.





RE: concrete walls out of plane - vertical rebar is the only valid risa design result, horizontal is not
RISA doesn't use the local plate forces for reinforcement design, so this is irrelevant. RISA instead uses the plate corner forces / nodal forces to determine reinforcement requirements.
Regarding your foundation wall:
RISA's wall panel element was NOT derived for foundation walls. Rather it was derived primarily for shear walls and bearing walls. In these cases, the horizontal reinforcement is there to resist shear forces (and for T/S). It can be used for out of cantilever walls subject out of plane loading because that type of bending is a significant consideration in the design of shear walls and bearing walls.
At some point, it could be expanded to include the horizontal out-of-plane bending. But, these things are never as easy as they seems when you think about the one simple case you're looking at. If we were to do this in RISA, we would have to make it work for all types of walls. How would that work for shear walls with openings? How would that reinforcement requirement interact with the reinforcement already present for shear? Not saying that these issues can't be worked out, but just pointing out that the GENERAL case is considerable more complicated than your simple foundation wall.
RE: concrete walls out of plane - vertical rebar is the only valid risa design result, horizontal is not
I sure hope that the program does this in the future. For now, I'm just glad I noticed that it didn't do it.
It would be helpful if the results stated something like, horizontal steel is not designed for out of plane bending, in big red letters.