Torsion design in beams

[allimuthug]

Please see the picture of sleeper supporting pile load over it. The torsion is assumed to be on the pile cap 650x 1000mm.
Minimum reinforcement in ACI has
(Av+2At) = 0.062*(fc^0.5)*bw*s/fyt

bw is the web, for torsion design of pile cap bw should be taken as 650mm, not 1000mm. can anybody clarify with an example.

[link

http://files.engineering.com/getfil...4a9-af17-2e69db461502&file=TORSION_DESIGN.png

]Link[/url]

 

[jayrod12]

When it's torsion, you take your smallest dimension since the torsional stresses are equal around the perimeter of the cross section. at least that's how it was explained to me.

 

[allimuthug]

Hi anybody can give an example of torsion design of beam where breath is greater than depth, as shown in the picture above.
Since some of them still feel that bw is web width = 650 mm as per above figure.

 

[jayrod12]

As I said, a beam subjected to pure torsion (or essentially pure torsion when vertical loading is minimal) doesn't care whether it's vertical or horizontal, design procedure is the same for the torsion side of things.

 

[KootK]

I agree with Jayrod on all counts so far.

As we've discussed previously, however, I feel that strut and tie would be a better choice than sectional methods here based on your proportions.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.