Parking Structure Subjected To: Roof Party - "Gangnam Style"
Parking Structure Subjected To: Roof Party - "Gangnam Style"
(OP)
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Parking Structure Subjected To: Roof Party - "Gangnam Style"
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RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
I feel similar movements in my car as I sit on an overpass (constructed of pretensioned concrete I beams) waiting for the light to change while traffic is passing to either side of me. I don't even have to play music to rock out!
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
"The average passenger vehicle weighs approximately 4,000 pounds, which is equivalent to 26 people that weigh around 150 pounds each. For clarity, that's 26 people per parking stall. If the parking garage can withstand the weight of hundreds of parked and moving vehicles (and their passengers), I don't think that people dancing on the top floor will cause a structural problem."
This guy would be shocked to find that parking garages are designed for 40psf which was recently reduced from 50psf.
Years ago my now wife was living in an apartment next to a major university in a large metropolitan area. She lived on the first floor with a bunch of college kids living above. They used to have dance parties above and you could literally see the floor deflect up and down as they would jumped in unison. Plaster was falling from the ceiling. Had something happened I'm sure their parents would have sued the building owner, city inspector, contractor and anyone else involved. Our future leaders hard at work.... ugh.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
Figure 5 people in a 5 ft. x 5 ft. area each weighing 160 lbs. each.
That is 800 lbs in a 25 s.f. area = 32 psf.
Assume a dynamic impact factor of 2.0. That equates to 64 psf. (don't know if the 2.0 is accurate or not - I pulled it out of the er, air.)
If the garage was designed for 40 psf. Using LRFD that would be an ultimate capacity of 40 x 1.6 / 0.9 = 71 psf.
So perhaps it was almost at collapse.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
Of course, we don't know what the design really was, do we??? Was the designer competent?
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
There is a pretty substantial cable suspension pedestrian bridge near me. Just from shaking the cables lightly I am pretty convinced that one or two people could bring it down if they wanted to.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
Mike McCann
MMC Engineering
http://mmcengineering.tripod.com
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
Just so that we are clear, that wasn't my load of 26 people per stall. That was a comment made in the video by someone who said that the structure should easily be able to take the load of the people because the structure is designed to support vehicles.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
How many ASU girls does it take to bring down a parking garage?
[/shameless school rivalry]
Also saw this in the comments:
"Just FYI, we did this last year too. After the intensive bouncing, the facilities manager double-checked with a few engineers and people who had been responsible for the construction of the parking structure and got the OK to do it again this year."
Now can we consider fatigue too?
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
http://www.youtube.com/watch?v=CMCXjZ3xuEc
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
So a student said a facility manager said that he/she double-checked with a few engineers, and people (contractor's apparently), who said that the original design was fine for anything a mob of inebriated teens could dish out. How about a sealed report?
Seriously tho to Ron or Mike or some of you guys with experience in PT component manufacture/testing/approval...Are these panels ever tested to failure under heavy dynamic loads (light load at high amplitude near the natural frequency)? My initial thought was that this type of loading was obviously damaging, but it may not be as bad as it looks if the load never exceeds the cracking moment or causes a stress reversal of the pretensioned member.
Thanks all.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
In our city there are two parking structures in the downtown area. Every fourth of July the top floors are filled with people watching the fire works. This of course is on top of all the parking spots full. I am hoping that the structures are designed for 100 psf at that level. Perhaps the codes should consider a change to top floor parking.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
However, we don't get a lot of parking structures that fall down because of occupancy loading, so I can't really argue that this is a real problem, but I've spent a bit of time worrying about this on several occasions.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
With respect to allowing people load on the top garage level: Normally, the roof top of the garage is not designed for such a live load. The owner should not allow such an event to take place and the fire marshal would be very upset.
With respect to designing garages for a greater people load on the top floor: You really can't because that would be considered a different use (mixed use) and you will be unable to get a building permit as a garage. It would require more stairs, fire sprinklers, etc.
www.PeirceEngineering.com
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
http://www.standard.net/stories/2012/05/24/25-year...
The moral: densely packed people are much heavier than cars, though the majority of the general public would think otherwise.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
Since this was in Arizona the most likely snow load is 0psf. I am interested is seeing how you figure out how much snow load would be piled in the the designated areas? I have always wondered how this was done. I have been asked to look into this before but the projects have always fell through.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
We have detremined the density of ploughed piled dense wet snow by actual measurements on site in downtown Toronto.
We limit the pile height and design the designated area for the corresponding load. Usually > 200 psf.
This is certainly not ideal for a number of reasons, including enforcement of pile area and pile height (say 5 feet), but we have seen garages where no snow load piling was designed for and yet we saw large snow pile with no visible distress.
In most garages the snow is removed by ploughing it into a snow melter (for larger garages like the 10,000 car garage we designed), or for smaller garages it is ploughed over the edge at barriers that open to allow the snow to be ploughed over the side Or down a shaft), or other snow removal methods.
Too bad that Arizona gets no snow. There is nothing more beautiful than to watch a raging snow storm (while looking out the living room window) or out walking thru a blinding storm.
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"
RE: Parking Structure Subjected To: Roof Party - "Gangnam Style"