Prestressed Concrete Bridge Girder Lateral Stability

[TS59401]

I have been asked to design some temporary bracing for a ~160ft pre-stressed bridge girder. I am looking at the lateral stability of the girder with respect to an article by George Laszlo (attached); specifically lateral stability for plant and field handling on page 90 of the article. If I run the numbers on my pre-stressed beam I get a F.S. < 1.0. Does this mean my beam does not have enough lateral stability to rest on its bearings (abutment and pier) without bracing it along the span, or am I misinterpreting something? Page 90 shows how "Yt" can be increased to increase the F.S. but I am unsure how that applies to a beam supported on its bottom flange. I just want to make sure I am understanding these results before I require bracing at mid-span. Thanks.

 

[TS59401]

My apologies; I did not get the link correct in the first post. Please see my second attempt attached below. Thanks again.