Vehicular Railing Load 1

[jdblake]

I'm trying to design a 42" tall concrete rail that sits on top of a gravity modular block wall. I understand that there is a 10 kip design impact load at the top of the rail but I don't understand how that load is distributed. AASHTO says that it is distributed along the length of 0.8X+3.75', but X is for post spacing and not applicable since the railing is continuous concrete. Is it practical to take this 10 kip load into a klf load? If so, how?

 

[miecz]

The Standard Spec distributes the 10 kips to 5 feet per Article 2.7.1.3.6.

 

[jdblake]

Thanks miecz. Exactly what I was looking for.

 

[zdude]

Just a quick followup.

I have a little background in bridge design. Consequently, I have looked at concrete rails such as the one you are describing as being similar to bridge rails. The LRFD design manual Table A13.2-1 gives a force and a width to apply the force based on test level. The lowest design level is 13.5kip over a 4' longitudinal width.

Am I talking about a completely different topic?

 

[jdblake]

I think we're talking about the exact same topic but I'm not using the LRFD AASHTO Manual because I don't have one but I do have the 2002-17th edition. Why is the LRFD loading greater 150% greater than 17th edition?