Cranked concrete beam 1

[hoshang]

Hi all,
What considerations one should take in analysis and design of concrete cranked beams? If my query isn't clear, I can upload images. I searched this forum for cranked concrete beams, but without success.

 

[hoshang]

I apologize for my frustration, but I don't think you're quite getting what I'm getting at. We all gave you a bunch of comments/considerations earlier. You haven't done anything with any of those.

If you followed the thread one by one, I asked some elaborations on the comments.

Why are you asking about this beam if it's not to help you in the design? I'm just not sure what you're after.

As I stated, to exchange opinions and discussing pros and cons of the suggestions.

 

[jayrod12]

But you aren't contributing. Contribute some of your knowledge. Ask specific questions about the suggestions given forward. I feel you're the one missing the intent of this website.

 

[hoshang]

But you aren't contributing. Contribute some of your knowledge.

Please find the attached picture. The red rectangles are my suggested column positions. The green lines are my suggested beams. My thought is that these will support quarter turn stairs and the cranked beams. Your opinion would be highly appreciated.

 

[jayrod12]

Yay! that's exactly what I was thinking in terms of outrigger beams. Those green lines extending downward to grab your cranked beam. I would also be incline to agree with your proposed column locations for the new ones. You could maybe delete the upper additional one and just run the beam back to the left-right beam you're showing. But yes, I think doing that at each stair would make the analysis, and the performance, much better.

Doing that would also likely remove the torsion/bending continuity concerns that KootK brought up.

 

[hoshang]

You could maybe delete the upper additional one and just run the beam back to the left-right beam you're showing

Can you explain this, please?

 

[driftLimiter]

He is saying you have a beam along Grid Line 4 and the backspan of your outrigger could just frame into that without needing another column ong GL 4.5

If you do this then you will still have a cranked concrete beam (actually 2) but it will have a much more reasonable span.

The cranked beam goes from B+ to C and from E to E+

 

[hoshang]

without needing another column ong GL 4.5

I suggested this column to help supporting the landing.

 

[dik]

Unless the outer load on the cantilever is significant, the added framing will not help appreciably and will cost a lot more money. IMHO

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoshang]

Unless the outer load on the cantilever is significant, the added framing will not help appreciably and will cost a lot more money. IMHO

I made this thread for discussion so others would provide recommendations, solutions, finding weakness points, discussing load paths.. etc. Your valuable contribution is highly appreciated.

 

[dik]

I'm just one of many engineers on the site. Collectively we have a wide range of experience. I'm glad we could help.

-----*****-----
So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[hoshang]

without needing another column ong GL 4.5

Unless the outer load on the cantilever is significant, the added framing will not help appreciably and will cost a lot more money. IMHO

I suppose you both mean the quarter return stair doesn't need column to support its landing.