Wind Design for Flat Roof Carpark
Wind Design for Flat Roof Carpark
(OP)


Good day everyone!
I am a newly grad.. Can you help me on the Wind Design Calculation of flat roof carpark?
I will design a carpark with flat roof and no enclosing walls.. supported by circular hollow steel section columns.






RE: Wind Design for Flat Roof Carpark
RE: Wind Design for Flat Roof Carpark
Professional Engineer (ME, NH, MA) Structural Engineer (IL)
American Concrete Industries
www.americanconcrete.com
RE: Wind Design for Flat Roof Carpark
In Canada, our codes and design guides don't specifically cover wind loading on this type of structure. I analyzed a similar structure recently but struggled in determining an accurate wind loading value and what should be considered for partial wind loading.
1. To determine roof uplift, I used the typical roof suction combined with the internal pressure for Category 3 (buildings with large openings through which gusts are transmitted to the interior). Does anyone have a comment on if this is an acceptable application of Category 3 internal pressure?
2. In calculating overturning moment, I considered partial wind loading comprised of 100% of the uplift on half of the roof and 50% of the uplift on the opposite half of the roof. This case was not explicitly covered by the code but I felt it was a rationale approach. Does anyone have a comment on partial wind loading on this type of open structure?
Great spirits have always encountered violent opposition from mediocre minds - Albert Einstein
RE: Wind Design for Flat Roof Carpark
Good luck,
Dave
Thaidavid
RE: Wind Design for Flat Roof Carpark
Check your reference codes for the actual requirements. I've designed hundreds of similar canopies in the US and other areas. They are "monoslope roofs over an open structure" for general characterization of where you might start. Wind loads will have to be checked in multiple directions to determine the worst condition.
RE: Wind Design for Flat Roof Carpark
RE: Wind Design for Flat Roof Carpark
I would try and get an upper-bound solution to this problem..
Main members and fdns
a)for wind perpendicular to the long direction, I would assume a deflection/rotation of the roof
of say a value of alpha between 20 and 30 degrees and blocked underneath. Check the theoretical
deflection/rotation using those values. May back off on the values of alpha if the theoretical
value of deflction/rotation is much much less than the assumed values. But also realizing that
the deflection/rotation of the fdn is an inexact science depending on type of fdn used.
b)for wind parallel to long direction...probably no significant rotation of roof except, perhaps,
for the leading edge.....
c)check wind for from multiple directions
Cladding
use values in applicable codes in combination with the above assumptions...
RE: Wind Design for Flat Roof Carpark