Rule:unsupported span and spacing

[Hisham]

Hi all

I have 2 siple questions

1- in longitudinal systems what is meant by unsupported span for the deck center girder ?
is it the spacing between (transverse Web Frames) or the distance between the two BKHD that are carrying the CG ?

2- if the member under consideration is deck girder, what the classification society means by saying spacing? dose they mean transverse frame spacing or spacing between longitudinals?

hope to find the answer here?

thanks all

[Arvy]

Hiya,

Kinda difficult to answer these simple questions out of the blue. A counter question is: which rules are you using?

In GL rules the unsupported span of anything is the spacing between other structural members that are holding the member under investigation... so it would be the transverse framespace when you are talking about the longitudinals. I hope this kinda clears it up but it is hard for me to explain in english (and I also hope this is correct as I am using this for my calculations as well). Besides this spacing the GL rules give you a minimum unsuported length you should use if you unsupported length is longer (in my case the unsupported span is always shorter, so I use the minimum length).

The second question can only be answered within the context of the rules you are using. I will have to look it up for the GL rules.

One last remark, never interchange rules from one ruleset with another one.