Pittsburg Convention Center failure 5

[JAE]

This article on ENR is about a failed section of floor at the Pittsburg DLL Convention Center. I note the following statement from the article:

[blue]The structural-steel slip connection of a girder at the X-9 expansion joint that runs in the short direction of the David L. Lawrence Convention Center in Pittsburgh is a detail that at least some structural engineers don’t favor, a source told ENR.[/blue]

http://www.enr.com/news/buildings/archives/070222.asp

I guess I’m surprised that anyone would design a thermal slip connection in framing where the slip occurs via bolts sliding in horizontal slots. What they describe happened was that the bolts eventually gouged out the hole and reduced the ability of the connection to slip.

I’ve for years never used this detail (not that I’m all that smart) but because I was taught that you use either double support beam/column arrangements or Teflon seats (which apparently is the resulting repair).

Is this expansion joint via slotted hole detail used that much? I’m just surprised it was used on a project of this magnitude.

 

[hokie66]

The ENR article highlights again the pitfalls of shop detailers designing connections. if that is indeed what happened. Remember the Hyatt walkway?

 

[vincentpa]

They are installing the original teflon bearing seats on all remaining beams. I forget how much the contractor saved on all of the connections but is was only like 5 or 10 grand! Be careful with the shop details!!! This convention center has had problems in the past also. The concrete floors are so badly cracked that even I was scared. I don't think they put any shrinkage reinforcement in the slab on deck. The floors are a mess. It turns out to be only a serviceability concern but it looks like hell and scared the hell out of the public. It's a shame because it is a beautiful structure and expensive!