STAADPro Tutorials Part 22 : Concept of Moment Release

In this lecture, you will learn the reason about moment release in secondary beams. You will also learn which moment should we release and how to achieve it at the site.
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[@parthadey4265]

Fantastic few minutes lecture, l love it sir❤

[@kritarthjhawar9418]

Very informative vdo series sir 💯💯💯💯💯💯💯eagerly waiting for design excel sheets and interpretation of staad pro results with manual results ....please teach us before Diwali....dil se thankyou !!!!😍😍😍😍

[@azmat_waseem]

Very Informative... Thanks...

[@hafizadnan592]

Sir please make a video on deflection control of longer span RCC primary beams using secondary beams

[@darshand549]

My question is @ the junction of primary beam & secondary beam, where the column comes. I didn't understand that part.

[@azmat_waseem]

@ 5:06 Time line you mentioned that, in order to release the Mz moment in Secondary Beam, provide Ld/3 instead of Ld. So my question is that "Is this releasing of moment in secondary beam is mentioned in any of the IS code? If yes, Please give reference." Thanks...

[@simplystructural8424]

Check SP 34 code for Detailing clauses

[@azmat_waseem]

@@simplystructural8424 Okay. Thank You...

[@azmat_waseem]

@@simplystructural8424 I think its Cl. 4.6.3, P45 of SP-34.
But, What % of moment release is to be done?

[@simplystructural8424]

@@azmat_waseem Generally we go for full release

[@azmat_waseem]

@@simplystructural8424 Okay. Thanks..

[@acharnandakumar]

V nice 👌 👍 👏 ✨ 😎

[@dsingha102l]

At 5:18, it is provided to satisfied ductile detailing as IS 13920

[@awes_rs2208]

Some engineers do not release moment why so ? And is it right to do that in some secondary beams where span through 2 or more compartment of building?

[@suvadipghosh7717]

Thank you sir

[@awes_rs2208]

At site there won't be complete release right ?
Then why complete release in staad ?

[@TarakParab2]

It's an ideal assumption. If you assume that secondary beam is simply supported on primary beam, or even on a column supports, that means in your analysis you will get zero fixed and moments. That means you won't design for fixed end reinforcement at top and provide minimum Ast.
At the same time, since you assumed release of support moments, that moment is redistributed to mid-span. Hence you will get higher depth of the secondary beam and or more Ast in the mid-span. But that reduces torsional complication of primary beam. And it is uneconomical to design for torsion compared to slight increase in depth or steel of secondary beams.
So, in reality, when secondary beam will be loaded to its ultimate capacity, rather than deflecting more and transferring more Mz to primary beams, it will deflect to lesser extent and Mz will quite less, not zero but fairly less.
And since you are assuming no tension at top, your top bars don't need full Ld as they are not being pulled to full extent.
Now, at site there won't be complete release, but the whatever partial release that happens due to lower deflection of secondary beam is sufficient to relieve primary beams from considerable amount of torsion. And the provided primary beam's section is able to handle that torsion.
You can check for that while designing. By considering maximum torsional capacity of the provided section of the primary beam, and deriving how much fixed end moment needs to be developed in the secondary beam to reach that capacity.

[@stillimproving7883]

​@@TarakParab2..Now it's very clear. Thank you sir