Wind Loads on Soundwalls - AASHTO LRFD Bridge Design Specifications (2013)

[UncivilEngineer]

It's unclear to me as to how to compute wind loads on soundwalls per the above-referenced AASHTO, specifically for wall heights less than 30 feet. Section 3.8 provides equation 3.8.1.1-1 for calculating Vdz to then use in equation 3.8.1.2.1-1 to calculate the design wind pressure (also reference Section 15). My question is, what value(s) should be used for Z (wall height) in equation 3.8.1.1-1 for wall heights less than 30 feet, considering the definition of Z below the equation states it only applies to heights greater than 30 feet? Should Z=30 feet be used for wall heights less than or equal to 30 feet, or is it permissible to use Z<30 feet, resulting in reduced calculated design wind pressure values?

I have designed several soundwalls, but always using either the older AASHTO Guide Specifications for Structural Design of Sound Barriers (1989), or ASCE/SEI. Thanks for the help.

 

[OSUCivlEng]

I struggled with this as well when I designed a soundwall. I think this should answer your question.

http://onlinepubs.trb.org/onlinepubs/nchrp/docs/NCHRP20-07(270)_FinalSpecs.pdf

 

[UncivilEngineer]

Thank you very much. As I suspected, this confirms to use z=30' for wall heights <= 30'.

 

[bridgebuster]

Thanks OSU for posting that paper.

 

[VoyageofDiscovery]

This is a great find! Thanks OSU.

 

[OSUCivlEng]

Yeah the wind load is pretty dang confusing to me. The TRB and NCHRP have a lot of great information, but they don't seem to make the design community very aware of it.