RC Shear wall analysis and design

[Anonymous]

Hi all,

I am trying to model and design an RC shear wall to resist the horizontal wind load. I am getting very high requirements for reinforcement, which is mainly concentrated at the corners (see attached screenshot) and looks unrealistic. Is there an option in robot for averaging the stresses or do you have an other ideas of how to approach this issue?

Thank you very much.

[saclovitzky]

look rc wall values at Tables/reduced results

[Anonymous]

I did that. It's just a table with results. The requirements for reinforcement remain the same.

[saclovitzky · Accepted solution]

If your wall is just resisting in plane forces(moments & shears), it is normal that the concentration of stresses are concentrated on wall edges.  This is a classical C and T analysis of walls. Reduced results will gives you an idea on the forces that's acting on it, and it is up to you to accept it or not.

The software will only match the amount of reinf. based on the generated internal stresses and again, we will decide
if it does makes sense.

[panosmavridis_eng]

What I usually do, is create a panel cut at 0.50m (more or less) from the edge and use the results on the cut to calculate the required reinforcment at the edge.

It is normal to have stress concentration at wall edges (or generally on edges). It has to do with the numerical analysis limits.

[Designer11011]

@panosmavridis_eng I am facing the same issue yet the required amount of reinforcement is huge in the web of the wall (6x10^6 cm^2) which is impossible to provide, the loads taken into consideration are not wind loads yet seismic loads. When removing the seismic loads from analysis, the required amount of reinforcement becomes resonable, is there any approach to solve this?

[panosmavridis_eng]

@Designer11011 

1. check if your mesh is correctly done

2. ensure that the seismic loads are the cause of your results. Before adding some more shear walls, reduce the ground acceleration and check if the reinforcement area is decreased accordingly. If so, you need to add more shear walls (or moment frames) to resist the earthquake.

3. check also if the horizontal displacements are within the limits  according to the code you are applying.

[panosmavridis_eng]

@Anonymous another nice approach is the core walls. You can get the internal forces of the wall  and then design the reinforcement in a software separately, like Idea Statica.