ASCE 7-10 Fig 7-2 Error???

[SteveGregory]

I am looking at the dashed lines and solid lines in the 3 graphs in Figures 7-2, ASCE 7-10 and comparing them to ASCE 7-05. Figures 7-2a and 7-2c are essentially identical. For ASCE 7-10 Fig 7-2b, the solid line at Cs=1.0 reads 45 degrees graphically but is labeled 37.5 degrees. For ASCE 7-05 Fig 7-2b, the solid line at Cs=1.0 reads 37.5 degrees graphically and is labeled 37.5 degrees.

Does anyone know what the solid line value in degrees for Cs=1.0 in Figure 7-2b should be?

 

[TehMightyEngineer]

Didn't see anything in the ASCE 7-10 errata. Does sound like an error though as I don't think anything should have changed. Is there a solid revision bar on anything on the figure in ASCE 7-10? I don't have my ASCE 7-10 with me to confirm.

Maine EIT, Civil/Structural.

 

[SteveGregory]

I just checked and there are no solid revision bars on the figures although there are some minor technical differences. For instance, there are some "R" value notes for warm roofs and there is a new cold roof with a Ct=1.3 now.

Also, I checked the commentary section out. They have mathematical formulas corresponding to the graphs. If the formulas are correct, then the 7-2b should have Cs=1 at 37.5 degrees. Maybe someone on the ASCE 7 Snow subcommittee could help us.

 

[SteveGregory]

I got a reply from the ASCE Subcommittee on snow. "This is a typo which I understand will be corrected in subsequent printings of ASCE 7-10 as well on the errata page which ASCE/SEI maintains. For Figure 7-2b the solid horizontal line should bend and begin to descend at 37.5 degrees, not at 45 degrees suggested by the figure.

Sorry for the confusion". Michael O'Rourke

 

[TehMightyEngineer]

Thanks for the follow up.

Maine EIT, Civil/Structural.