Can anyone provide more information as to how LeapBridge Steel CE V21 (Version 21.00.00.28) calculates the LL Distribution Factors? I have computed these by hand and I'm getting different results to those computed by the program. In Summary, I was getting > 10% difference when it comes to interior girder distribution factors for moment (both single and multiple-lane factors).
Somehow, after going through a "saved as" version of this model, the DF changed and matched hose calc'd by hand a lot closer but I cannot replicate these factors in the original LeapBridge Steel file.
Anyone know of a checkbox or simply a bug that can be causing this?
Thanks1
LEAP Bridge Steel performs live load analysis either by Line Girder ,Grillage or FEM methods by user selection. For line girder (similar to LBC) LBS computes the live load distribution factors using the AASHTO Formulas and bearing reactions are calculated . For grillage analysis and FEM analysis the entire bridge deck is modeled and analyzed so there are no AASHTO live load distribution formulas involved.
LBS program might have refreshed when the file was saved and then the LLDF values started matching your hand calculation.
For more information related to LBS please check this link
https://communities.bentley.com/products/bridge_design___engineering/w/bridge_design_and_engineering__wiki/20537/leap-bridge-steel-main-page
Answer Verified By: Dilip Matange [Bentley]
Thank you Vinay.
I found that the shear connectors needed to be there in order for the DF under the line girder analysis to match those that were handcalc'd.
Thanks for sharing such a helpful instruction, really appreciate for your article.
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