Simple Shear and Moment Analysis

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Simple Shear and Moment Analysis


I am working on a continuous 3-span unit, that is going to be a steel girder composite bridge. I was just trying to use the software to calculate the Shear and Moment loads on the given geometric parameters I have entered.

1.) I was wondering in the analysis results for "Final with LL (Bridge Site 3)" when I choose Strength I conditions does this include the dead loads or do those have to be inputted as "user inputted DL"?

2.) Is there anyway to modify the geometry of the girders to mimic a steel girder?

I have attached my design file if anyone has time to look at it and help me out.

Thanks for you time, Shane

Binary Data Capston I.pgs99.31 KB
Rick Brice
Shane, The Strength I load

The Strength I load combination includes all the dead loads and live loads. The dead load is generated based on the cross sectional area of the girders and deck and the unit weight of the material.
In the girder library, you can define a wide-flange I-girder to look similar to a steel I-beam. The key is to define a cross section and to define material properties so EA and EI come out correctly.
Also note that precast girder bridges are simple spans made continuous. In many steel bridges, the girders are continuous before the deck is placed. You'll have to take this into account.
You may consider using WSDOT's QConBridge application. This application performs a generic analysis on continuous bridge frame structures.
Richard Brice, PE
Software Applications Engineer
WSDOT Bridge and Structures Office

Thank you for the response. I

Thank you for the response. I was planning on using QCon but it keeps crashing once I try to run the analysis portion. Do you know why that might be? I run Windows XP.

Rick Brice
The most common reason for

The most common reason for crashes in QConBridge is a problem with the boundary conditions. Users frequently use a hinge or roller boundary condition at the same location as a moment release (non-continuous) boundary condition on the span members.
In the bridge model view, if there is a little open circle on all the beams framing into a hinge or roller support, then the boundary conditions are the problem. Change the boundary conditions of the beam members to Continuous.

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