Very Busy

I've been ridiculously busy at the office recently, meaning blogging has all but vanished over the past week. I'm so far behind and I still have a meme or two that I've been neglecting. Today I had a three hour long meeting that I probably only needed to attend for the 20 minutes that it pertained to me, but I had to sit through the whole thing anyway. I need to learn how to sleep with my eyes open.

So in the spirit of work, today I'll quickly touch on two structural engineering items:

1) The elevated highway collapse in LA Oakland - The interesting thing of note here is that the fuel from the gas tanker actually caused temperatures to reach the melting point of steel ~1510ºC (note that the temperature isn't exact as it depends on the proportion of the elements in the alloy), though this temperature is unnecessary to cause a structural collapse. Here's what happens to the strength of structural steel as it is heated.As you can see, even at half the melting temperature, the steel gets very weak indeed; though still a solid, the steel may no longer be able to support the applied loads and the structure will collapse. This is what researchers believed happened in the World Trade Center.(Image cred here)

2) I've been working as a structural engineer-in-training for almost 2 years but it's only now that I've finally seen something large that I've designed (I've seen some barrier walls I designed but they aren't very impressive). The sad thing is, it's only a temporary structure, so once it's done its job, it's coming down. The sadder thing, I haven't actually seen it in person. It's on a webcam. Aww, crap, they've changed the direction of the webcam since yesterday so you can't see it. Good thing I took a screenshot when I had the chance. So what is it? It's a support tower for the large roof trusses of an arena in Kingston, Ontario. I've circled it on the screenshot. The roof trusses are too large to be assembled on the ground so they assemble each one in two parts. One part is installed with one end sitting on the tower, then the other part is installed and the two parts are connected together. Move the tower to the location of the next truss and repeat.

So now you know: if the arena collapses during construction, I'm probably to blame.