Intermediate Stiffener<Spacing and Numbers>

[johny13]

how to find number of stiffener of existing bridge. i am doing load rating, need to enter stiffener ranges?

 

[ImminentCollapse]

Existing bridge? Can you look at the bridge and count them?

Otherwise, just use 4 and you're good.

Oh, you may want to consider the girder span, girder spacing, loading, web thickness, web depth, Fy, Fu, E, fb, V, M, flange plate dimensions, diaphragm spacing, point of contraflexure (only if continuous of course!), composite/noncomposite, tension field action, LTB restrictions ..........

 

[johny13]

For a reason,i dont want to count instead, want to get any equation to calculate Inter.stiffener.

FYI: Stringer schedule provides spacing of intermediate stiffener.

Also, should i add total number of stiffener from stringer schedule should to diaphragm connection plate too or it should be excluded from total number of stiffeners?

 

[Qshake]

Usually, the connection plates for diaphragms are excluded from web stiffener and shear calculations.

The old rule of thumb before steel prices went through the roof was that a designer would use a web thickness that precluded the use of stiffeners minus an 1/8". As a result, not many stiffeners were used on bridges, especially those with wide flange stringers. Stiffeners are more common on plate girder bridges.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[johny13]

the bridge (plate girder type) i am doing LR, was built in 1968. i asked one of senior engineer and he said to consider diaphragm connection plate as inter.stiffener.

what is your suggestion?

 

[Qshake]

If your using software to rate this bridge then try it without the connection plates as stiffeners. If runs ok, great. If not, then include the stiffeners.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.