Modifying ADOT Standards to suit Project

[anthony gravagne]

We have a client who has shown inlet and outlet wing wall lengths and wall slopes on his drawings which differ from the ADOT (Arizona DOT) standards in relation to concrete box culverts and concrete pipe culverts. I am having difficulty in determining when an analysis should be done when the project differs from the standard. The standards show many different possibilities such as skew, culvert height, etc.

Does anyone have any guidance they can share? I was hoping that I would have to design every inlet and outlet wing wall because the wall slope does not match the standards.

 

[BridgeSmith]

The length and height of wingwalls are chosen to prevent erosion of the slopes. If the material being retained differs significantly from what is assumed for the typical dimensions, it may be reasonable to adjust the sizes. You'd probably have to contact ADOT to get the definitive ansswer, but most likely, if the proposed length or height are larger, or the thickness is less, than the standard, structural design calculations would be needed. Otherwise, you could probably use their reinforcing, and they would approve it.

That said, if you develop a generic design spreadsheet, you can run designs for numerous different sizes very quickly.

Rod Smith, P.E., The artist formerly known as HotRod10