Wind uplift on prestress
Wind uplift on prestress
(OP)
I am getting more involved with the installation of solar water and electric panels on existing structures. Normally it is a simple matter of transfering the wind loads to the ground with proper selection of connectors. I have been asked to design a installation on an existing prestressed hollow core roof system located on the coast with uplifts in excess of 50 psf. I am concerned that the uplift will put the bottom strands in compression during a hurricane. I can not however find any information on such failures in the past.






RE: Wind uplift on prestress
Are you sure that you are adding a net uplift to the planks?
RE: Wind uplift on prestress
4 inches of concrete is approx 50psf.
Have you included the weight of the screed over, have you reduced the wind pressure for the roof area?
That said, I have had similar winds uplift a 36' x 7" wall panel in a shopping centre - I had to tie the thing down!
RE: Wind uplift on prestress
If the roof is existing, is it OK by your numbers without your additional solar panels? If it's not, maybe you're missing something the designer considered.
RE: Wind uplift on prestress
However if they are normal solar panels then you are probably not adding much if any net uplift.
RE: Wind uplift on prestress
IT is a simple calculation, basically your transfer calculation with a wind load uplift effect added. If there is tension in the top, there must be reinforcemnt to control the tension and cracking.
RE: Wind uplift on prestress
Hollow core panels have symmetric strands so they have good resistance to uplift as well as live loads. Their keying at the ends from the topping serves to hold them down as well as the relatively high dead load.