Did Construction Cause Collapse?

London Telegraph ^ | 8/4/07 | ReasonMcLucus

[HighWheeler]

Read my post above.

The higher the concentration of libs, the bigger the tragedy that follows.

[mamelukesabre]

It’s not the vertical force from sodiers feet. It’s vibration caused by them. The natural frequency of a structure is the one that creates standing waves. If an army marching in step happens to be marching at the natural frequency of a bridge when crossing it...standing waves result and the bridge falls.

The tacoma narrows bridge fell from standing waves created by wind.

[Rumplemeyer]

I worked on the “Big Dig”, if a concrete supplier furnished materials not meeting the mix design the resident engineer and his testing lab didn’t do their job, not the contractor.

[Rumplemeyer]

The fine was $50 million dollars, I don’t think that made cheating worth it, do you?

[Clam Digger]

Best bet is shabby construction in the first place and a lot of rake off by the contractors.

That is a low, sleazy slam. How do you think ythe thing stood 40 years if it was a bad construction job. Do you think all of us contractors are just scumbags who only rip people of? That's a really ignorant view. If it were true, wouldn't more of us be in jail?

How about wising up instead of making spurious, ignorant accusations.

[Clam Digger]

Oh, and WTF is rake-off? I’ve been in construction my whole life and never once heard that term.

[Clam Digger]

That’s a lovely bunch of Brits shagging us with bad concrete.

I put about 30,000 cy of their concrete in the ground, and every single bit of it I poured passed inspection by BPB (Central Artery prject management) inspectors.

[Clam Digger]

I was the chief enforcement investigator for a state Construction Contractors Board

Nice to see the guy who hecks on us contractors agrees we aren't the sleazes the ignorant folks try to mak us out to be. Yes, there are sleazes, but they don't last long, and very rarely are they in heavy construction.

[Ditto]

My background is in math and physics rather than engineering so I'm not familiar the precise distribution of weight and how the supports carried it, but the basic math would indicate more stress on one side of the bridge than the other.

Very unlikely, IMHO. If weight distribution could cause it, then bridges would be falling down with every traffic jam when one side is lined bumper to bumper all the way across and the other is virtually empty. A bridge cross twice every day is always backed all the way across on one or the other lane at rush hour.

[HighWheeler]

Isn’t the contractor ultimately responsible for all the material bought and people they hire? If not who is?

Someone has to provide the material specs to the suppliers, qualify the supplier, order the materials, then do on-site tests for things like at-pour concrete cylinders and steel samples for the lab tests. Who else would be responsible for that? Who hired the resident engineer and tesing lab?

[Rumplemeyer]

Mass DOT & Mass Turnpike Authority, they control the material specs, construction inspection and testing to prevent falsifying the results, didn’t work, but remember this is the State that keeps electing Null & Void to the US Senate.

[jurroppi1]

I couldn’t have said it better than myself! I’ve seen way too many mistakes made, in fact I rarely watch anymore because I find too many flaws to list...

[investigateworld]

"The higher the concentration of libs, the bigger the tragedy that follows."

That follows in everything, construction, law, medicine, defense ...

I've been involved in construction nearly all my life, and I would have to say, if someone approached the guys who do these big projects with an offer of a cheaper-non-approved materials,(Insert Eddie Murphy doing ambulance noises here)

And it probably does happen, but the consequences are too pricey. There is a number of checks and balances, including the most important thing of all, simple pride in doing a world class project, sounds corny, but these guys will drag their grandkids clear across the country to show off something they built.