Wind Load (WS) - LRFD 9th, Art. 3.8.2 - Vertical uplift load application

[Brad_SoKno]

I'm designing a steel girder pedestrian bridge, and I'm trying to figure out how to apply the 0.020ksf vertical uplift wind load per LRFD 9th, Art. 3.8.2.

I found a design example in the LRFD Ped Bridge Spec w/ 2015 Revs, but I'm not sure I fully understand how the free-body diagram works for determining the vertical loads on the windward and leeward girders. The design example shows the vertical load on the leeward girder as being 147.6 plf, but I've attached my sketch of the free-body diagram that shows the leeward vertical load should be 52.4 plf. I'm wondering if the design example calc's mislabeled the leeward and windward loads, or if I'm misinterpreting something?

I've searched Google far and wide for additional information or design examples, but no luck [URL unfurl="true"]https://res.cloudinary.com/engineering-com/image/upload/v1717865860/tips/Ped_Bridge_Wind_Design_Example_mdbdwx.pdf[/url]

 

[BridgeSmith]

It looks to me like the design example has it backwards. I think the 147.6 plf is the uplift to be applied to the windward girder.

 

[Brad_SoKno]

Yeah, that's what I was think but wasn't sure if I interpreted the statics correctly since they didn't show a free-body diagram with the design example... thanks BridgeSmith.

Brad