Recent content by chief

Just finished The God Delusion. Dawkins comes off bitter, but it is a good book. Currently reading Survivor by Chuck Palahniuk. Disturbing, but interesting.

Amen. I love how everyone becomes an expert in structural engineering after something like this happens. Reminds me of all the "bombs in the world trade center" talk. Maybe Bob slept at a Holiday Inn Express last night? :biggrin:

You missed my point. Of course you can make longer spans without supports in the river. http://www.aerialdelivery.net/images/TwinFalls/DSC00598-1.JPG You said commented about how the "steel support doesn't extend into the ground." You don't want to extend exposed steel down into the...

I'm not saying the jackhammer caused the collapse, but it could have contributed. I think corrosion and fatigue were the main problems... but since only 2 of the 6 lanes were open at the time of collapse, something else must have played a part. Otherwise it would have collapsed on a day when it...

You can't extend a steel column down into a river. It would have corroded 30 years ago if they'd done that. Since this bridge stood up to 40+ years of continuous loading/unloading, I don't think this was a design flaw. It sounds more like a corrosion/maintenance problem that was not...

You don't have to have steady vibration at the resonant frequency of the truss to cause fatigue stress in the connections. I'm a licensed structural engineer by the way.

Actually the jackhammering could have played a part in the collapse. If there were already corrosion problems and fatigue cracking in the welds, it is very possible that the vibration from the jackhammer amplified the problem and was the immediate cause of a truss connection failure... which in...

Also, there is a time lapse video of the collapse on http://www.cnn.com/.

BEFORE: AFTER: Who knows what caused it... the bridge was undergoing resurfacing and other 'minor' construction. Not sure what that means, but it might have had something to do with it. A failure of just one of those truss connections could cause the whole thing to come down. They said it was...

I'm a little late here, but I think I can help. The modulus of elasticity can be found in the NDS (national wood design code) tables. You just have to know a few things... the wood species, how the wood was graded (mechanically or visually), that actual grading (no. 2, dense, etc.), and the size...

That was my first thought as well. Imagine what this would look like from space. http://news.nationalgeographic.com/news/2007/02/images/070226-sinkhole-photo.jpg

http://www.space.com/scienceastronomy/070605_mars_hole.html http://apod.nasa.gov/apod/ap070528.html Pretty interesting. Sorry if this has been posted... I didn't see it anywhere.

Well, right now you just need to decide between mechanical and civil. With a degree in civil engineering you will be able to go into structural or geotechnical. I would pick the one you are most interested in and not let the issue of finding a job down the road effect your decision at all. It...

You have to know several different things before you can answer that question. 1) end restraints (it is common to assume that both ends are pinned or free to rotate) 2) moment of inertia of the section (about both axes) 3) unbraced length of the strut in compression 4) the amount of load...

I'm a structural engineer. If you get a job with a good firm that works on big jobs, it is a pretty interesting profession. If you get a job at a smaller company, you might end up doing smaller "cookie cutter" type stuff over and over again. Structural engineering is a branch of Civil...