Continuous Bridge LiveLoad with Varying I
Continuous Bridge LiveLoad with Varying I
(OP)
Has anyone found good software or a method of calculating live load moment envelopes on a continuous bridge? I have a structure length that is beyond AISC Moment Shears and Reactions tables, and I would like to verify my Visual Analysis results against something. The key is that the section properties vary along the span lengths.





RE: Continuous Bridge LiveLoad with Varying I
RE: Continuous Bridge LiveLoad with Varying I
Is there a method of moment distribution using variable section properties?
RE: Continuous Bridge LiveLoad with Varying I
You can interpolate between between the 1.2 and 1.3 tables. If the variation in the moment of inertia is not drastic, the tables are a good approximation.
Yes, moment distribution can be used for members with a variable section; just look in a book on structural analysis.
RE: Continuous Bridge LiveLoad with Varying I
I'm am familiar with the methods of moment distribution using different section properties for each span or frame unit including sway, from the analysis books I have. Are you aware of a reference that would have nodes mid-span where section properties change?
RE: Continuous Bridge LiveLoad with Varying I
Other than that, I use the moving load generator in GT-STRUDL or RISA for this, but those are a bit costly I think for just checking your analysis.
RE: Continuous Bridge LiveLoad with Varying I
RE: Continuous Bridge LiveLoad with Varying I
RE: Continuous Bridge LiveLoad with Varying I
Try the software from Washington State DOT:
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This package should be capable of creating the envelopes you are trying to verify.