multi-span continuous bridge

[rabi24]

Hi all,

I have a three-span continuous bridge. I am undertaking a project which involves comparing the live load distribution factors obtained by AASHTO LRFD formulas to the distribution factors obtained by finite element analysis. I have obtained the distribution factors from LRFD, and I have obtained the maximum moments/shear from FEA. I am having trouble obtaining the maximum effect to divide the FEM results by in order to arrive at a distribution factor. Any help is appreciated.

Cheers

 

[yakpol]

You need to find shears and moments in two-dimensional continuous beam due to a single lane of traffic and to multiply them by AASHTO distribution factors.

 

[rabi24]

Thanks for the reply.

How would I go about doing that?

 

[yakpol]

I am not sure what you are asking. How to find forces in continuous beam? FEA you performed surely was more sophisticated than to model a few frame elments.

 

[edward1]

Take finite element maximum moment and maximum shear and divide by 2D model max moment and max shear. Multiply this fraction by the LRFD distribution factor and this is the actual distribution factor to be used in the 2D model.