Temporary Tent Structure....Open or Enclosed?

[bigmig]

I am working on a project that is basically a temporary hospitality structure....The structure will be surrounded by a curtain system that will be shut during inclement weather and evening security. The structure is totally open during good weather and use. I'm seeing the wind load calculation as both enclosed and open, taking the worst case. Does anyone have an opinion on this?

The structure will only be erected for 7 days. Does anyone know of any short term considerations I should use for determining my wind loads?

Thanks in advance.

 

[BadgerPE]

I would agree to check the structure with both wind cases and then design for the worst case.

As for short term loading considerations, I would not be comfortable reducing the loading due to the relative short life span of the structure. See the attached thread for a more in-depth discussion of short-term load reduction.

 

[structSU10]

I think that would be the right approach.

And ASCE has a document for construction loading (ASCE 37) that may be applicable.

http://cedb.asce.org/cgi/

http://WWWdisplay.cgi?166170

This paper discusses the issues as well if you want to pay for it. I have only read the abstract myself.

 

[woodman88]

The ASCE 7-05 Commentary Section C6.5.5 along with Table C6-6 and C6-7 (for wind) gives some good information about this.
Note that Iw is based on Table C6-7 conversion factor values squared. So MRI = 100 years gives 1.07 when squared is Iw = 1.15 and the 50 years gives Iw = 1.0, then 25 years gives .93 when squared is the Iw = 0.87. So if you have a structure standing for only 5 years it would give an Iw = 0.61.
The squaring is due to the conversion factor being multiplied to the V factor before it is squared in the wind equations.

Garth Dreger PE - AZ Phoenix area
As EOR's we should take the responsibility to design our structures to support the components we allow in our design per that industry standards.

 

[Ron]

Agree with the other comments; however, consider that it only takes a 4 sf opening to go from enclosed to partially enclosed. I would not consider a tent as enclosed because of the deflection that will occur during wind, thus lifting side flaps, etc. Consider worst case of partially enclosed and open.

 

[zcp]

PLASA / ESTA ANSI E1.21 will help you a good bit. Section 3.5.2 is wind loading. Check into the operations management plan portion as well.

ZCP

http://www.phoenix-engineer.com