Wind Uplift Loads on an Open Structure 1

[PEFLWI]

I am designing a canopy structure. Since there are no side walls, I consider it an open structure and thus there is no uplift wind pressure on the roof. According to Table 26.11.1, the value of GCpi is zero for an open building. There is wind load on the framing members. Is this how you interpret this part of ASCE7?

 

[HTURKAK]

This is also a canopy.. The thread giving info. how uplift works..

https://www.linkedin.com/feed/update/urn:li:activity:6729645167499870208/

Car ventilation with wind uplift..
thread507-475858

 

[GC_Hopi]

I am guessing you are looking at an older version of ASCE 7 but ASCE 7-16 has equation 27.3-2 for open buildings for determining the uplift pressure.

 

[PEFLWI]

HTURKAK:

I have a different situation where the building is open on all four sides.

 

[WARose]

ASCE 7-10 has wind uplift forces for roofs of open buildings. See Figures 27.4-4 through 27.4-7. For C&C see Figs. 30.8-1 through 30.8-3.

 

[STpipe]

PEFLWI,

There would be uplift on the roof from wind. The pressure coefficients and different cases to consider are outlined in Fig. 27.3-4 to 27.3-7. The clause in Chapter 26 which says GCpi is 0 relates to the equations where you add your external pressure coefficients (GCpe) to the internal pressure coefficients.

Since this is an open building, all it's indicating is that you don't need to add an internal pressure coefficient because they will be zero, but you still have the external pressure coefficient.

Edit: WARose beat me to it.

 

[Ron]

PEFLWI...I've designed over 600 canopy structures, most of them in high wind areas. They all have uplift. I'm assuming this is a monoslope canopy. The roof is a component/cladding, that transfers wind load to the primary frame. If you look at the components and cladding tables in ASCE 7 for monoslope roofs on open buildings, you will see the appropriate factors necessary to compute the uplift.