dock floor collapse at convention center in pittsburgh

huangyhg

dock floor collapse at convention center in pittsburgh
at the david lawrence convention center in pittsburgh, pa. i saw this on the news and thought it would get a good discussion going. a section of the 2nd floor collapsed under a truck at the loading dock, leaving the front of the truck hanging over the street below. i think this is steel conctruction with a concrete deck. perhaps someone who works in pittsburgh took some better pictures, but here is the link to the news story:
6" slab seems a bit thin to support an hs20-44. most bridge decks are 8" minimum.
a closer look at it makes me think that it might be precast double tees with a topping. i am somewhat surprised that you don't see lots of reinforcing bars and strands hanging from the opening.
convention center loading is unique: motocross races, ice shows,monster trucks on 6-20 feet of soil base, sales and display of all types of products including terex, deere, caterpillar.  thousands of patrons using all parts of the facility and usually no upper limit on structural budget for municipal ownership. agree with the thickness comment from jike, 20' span needs more depth.
here's another article from today:
the description in the text implies that the contruction is steel girders spanning along lines of concrete columns with steel beams framed into the girders and precast deck slabs spanning between beams. or maybe i'm reading too much into it.
i'm about 2 hours away and unfortunately can't justify the road trip at the moment.