Good evening,
I need to model and study the following reinforced concrete geometry. I cannot find any information on this particular case concerning reinforced concrete ribs in the online help.
Could you please indicate a modeling approach that would allow for compliant reinforced concrete checks?
The section above is shown in red in the plan view below. The raw structural levels are a bit complicated, and the slab thicknesses vary. The load to maintain the +0.00 level on a lower slab is not a problem for me (a permanent load will suffice), but I cannot find how to model the structure offsets so that the reinforcements are correctly detected and verified, as well as the reinforced concrete sections.
The beam forming the opening frame is lower than the two beams that appear "vertically" in the plan view below. I am curious to know how to properly model this offset.
Hi FredericBourgeon,
thank you for your question.
The Member type Rib can only be used with surfaces lying in the same plane. Therefore, a different approach is needed.
If you want to analyse the shown detail as a member, I recommend the following procedure:
- Model the two slabs and the member in its original position.
- The lower slab and the member can be connected directly as they lie in the same plane.
- Connect the lower slab/member with the upper slab using a Rigid Link (line-line-connection type).
- Create the combined cross-section of the rib with the desired reinforcement layout in RSECTION.
- Assign a member of type result member with the created cross-section of step 4 to the line of the upper slab.
- Design the result member with the Concrete Design add-on.
The use of RSECTION is necessary because there's currently no equivalent cross-section in the library that is compatible with the concrete design add-on.
If you don't want to use RSECTION, you won't be able to consider the lower slab in the rib design but only the upper one. If you want to use this approach, assign a rib member to the line of the upper slab and connect the lower slab to the upper slab using a rigid link:
I'm happy to answer any open questions.
Best regards
Clemens Gutmann
Thank you Clemens. I feared something of the sort, but as long as there is a workaround, it's acceptable.
Two questions arise:
- Isn't the section type TUOF or TU2OF compatible with the concrete design add-on?
- Is there a way to analyse a stepped section concrete rib? The beam that appears on the horizontal axis has a stepped section (the right side is 140 mm taller than the left side). If I chose a rib type, the concrete beam is discontinuous and I cannot have a proper analysis. Should I rather scrap the rib "additional" stiffness and go for a continuous beam, stepped sections and rigid links to stitch the slabs and loads back together?
