Comments (10)

  1. PS3KIZ (February 18th, 2008 at 8:13 am)

    it dosnt look like concrete anymore

  2. SEXYDIVABABE (March 8th, 2008 at 5:51 pm)

    hu wud b abke 2 drive on da bridge doh lolz..

  3. floatpool (March 8th, 2008 at 7:00 pm)

    If you look closely you can see George Bush running with a detonator from the scene. 67 years later he causes the I-35 bridge in Minnesota to collapse. He’s quite the conpiracist.

  4. mano3obe (February 9th, 2009 at 1:50 am)

    would have been cool to be on that. Great engineering by the Americans that bridge lol

  5. KingLord32 (July 8th, 2009 at 1:11 am)

    It’s look like Bridge Is drunkly..

  6. mumbomum (August 10th, 2009 at 2:54 am)

    wait , why the fuck was it doing that?

  7. redrum420k (August 17th, 2009 at 5:53 pm)

    im pretty sure the car wouldnt be stuck on the concrete

  8. grendizerzero (September 10th, 2009 at 4:01 pm)

    Here, the wind has caused the bridge to start vibrating at a frequency very close to the “natural frequency” of the bridge, which compounded the bridges’ normal vibration to what is shown. This (natural frequency) is a factor that must be considered in the design process. There was a mistake here, and it is rumored that the designer committed suicide afterwords.

  9. TheElephant79 (November 4th, 2009 at 10:35 am)

    Holy shit

  10. a_structural_engineer (November 13th, 2009 at 4:04 am)

    The bridge exhibited a phenomenon known as aero-elasticity, resulting in aeroelastic flutter. The problems was that the bridge was unusually shallow and therefore had a relatively low frequency torsional mode (resonant frequency). This mode was excited by steady wind speeds of around 40mph. It worked in this way – the twisting bridge presented a sloped surface to the wind, which would drive it up or down (depending on the orientation), and once the bridge deck reached the top of its response, it would rotate and present the opposite slant, at which point the wind would drive it the other way. This meant that the motion was self-sustaining. Suspension bridges do not have much damping, so once the motion got going, there was not much that would stop it, except by the wind speeding up, slowing down or becoming more gusty/turbulent.

    The designer Leon Moisseiff, had also been involved in the design of the Golden Gate Bridge, and at one point it too was close to exhibiting this behavior, but the wind died down. It was subsequently stiffened torsionally to prevent this problem. Moisseiff died of a heart attack in 1943, not by suicide, but it was said that the disaster broke him. It is difficult to blame him, because this phenomenon was not really known at the time, but it was not the first time that such a collapse had occurred. It is said that the older Brooklyn Bridge has diagonal cables precisely to prevent this kind of response.

    At the time of the collapse, studies were underway at the University of Washington in one of the first wind tunnels in the world, which was constructed specifically to investigate this problem with the bridge – already known as “Galloping Gertie”.

    http://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_%281940%29

    For years afterwards, bridge designers hesitated to build shallower decks, and it was only by using a stiffer box deck and after extensive studies that the Humber Bridge deck went shallower.

Write a Comment