ASCE 7-10 Figure 28.4-1
ASCE 7-10 Figure 28.4-1
(OP)
I am looking at the low-rise envelope method in ASCE 7-10, and I am confused about it. They changed the cases from longitudinal and transverse to Case A and Case B. Case A does not include any sidewall pressures and Case B does. It seems to me that Case A is nothing more than Case B without sidewall pressures. Is that right? If it is what is the point of Case A.
Also, there is nothing showing the 2/3 roof zone boundary when the wind is along the ridge, but the Note 8 is still there defining that transition, but the pictures don't show it. Am I missing something, or is there a mistake? The latest errata I have is from January 2011, and I can't find anything more up to date.
Does anyone have a resolution for this?
Thanks
Also, there is nothing showing the 2/3 roof zone boundary when the wind is along the ridge, but the Note 8 is still there defining that transition, but the pictures don't show it. Am I missing something, or is there a mistake? The latest errata I have is from January 2011, and I can't find anything more up to date.
Does anyone have a resolution for this?
Thanks






RE: ASCE 7-10 Figure 28.4-1
Case A perpendicular to the roof apex generate global shear
Case B parallel to the roof apex generate no shear, just local pressure on wall that must added to interior pressure.
Case B is important in moment frame design.
RE: ASCE 7-10 Figure 28.4-1
Of course it depend of the geometry of the building (width of each frame side)
RE: ASCE 7-10 Figure 28.4-1
There will be global shear since both opposite faces are of different signs (i.e same direction).
RE: ASCE 7-10 Figure 28.4-1
RE: ASCE 7-10 Figure 28.4-1
- Case A generate a global Shear,
- Case B generale no global shear. See Pressure 1 & 4.
Of course Case B generate shear but in the other direction lateral force resisting system.