Details on Moving Load Optimization

Question:Hello,

I load rating a 3 span steel through girder bridge. The bridge has 2 girders spaced at 30ft apart with floorbeams running from girder to girder. The bridge is on a 21 degree skew. The travelway is 26’-0” wide and is centered between the girders. I would like to use the “traffic lane optimization” commands to find the maximum moment & shear on the girders and on the floorbeams.

However, I am not able to find the definitions of certain parameters in the help manual. For example, I am confused about the “Anal. Lane Offset” and “Margin” parameters. Can you please tell me what I need to enter into each of the “Traffic Lane Optimization Properties”?

Answer:Hello,

About the moving load optimization, kindly refer the image below. That would clarify what each option stands for.


So, for the vehicle positions and carriage way as posted by you, following should be the input:
Optimization Lane: 26'
Lane Width: 12'
Anal. Lane Offset: 2'
Wheel Spacing: 6'
Margin: 0'
Offset distance to lane center: The input here is the eccentricity of center of carriageway from the reference element in accordance to which the lane is defined.
Creation date: 10/28/2017 10:34 AM ()      Updated: 10/28/2017 8:07 PM ()
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