Bridge collapse in Minneapolis

[KY Thorobred]

It's really sad when stories come out like that after the fact. I would like to think routine checks are done to check on stability of buildings and bridges and will be interesting to see how this plays out.

 

CNN saying that it was checked in 2004 and everything was fine...Is it routine not to inspect a bridge annually? Especially one this big. I always hated going over the Clays Ferry bridge and this isn't going to help at all.

[Austydak]

I know in Kentucky the state inspector are "supposed" to do inspections twice a year if I am not mistaken. I maybe wrong but I think it is required. You would think they would have inspections at least yearly on bridges and other type constructions.

[HOMELESS CAMEL]

So if it was 2004, 3 years plus have gone, if that's the case that is inexcusable. ESPECIALLY considering the amount of traffic that this bridge likely sees on a daily basis. There will be just a "few" lawsuits coming out of this.

[KY Thorobred]

At least 6 dead

[nees1212]

So if it was 2004, 3 years plus have gone, if that's the case that is inexcusable. ESPECIALLY considering the amount of traffic that this bridge likely sees on a daily basis. There will be just a "few" lawsuits coming out of this.

 

It was inspected the past two years too.

[HOMELESS CAMEL]

It was inspected the past two years too.

 

Good to hear. Could very well end up being just a freak accident.

[nees1212]

Good to hear. Could very well end up being just a freak accident.

 

 

I don't know if I heard correctly or not as I was playing with the little one and trying to listen, but I think they were also working on the structure and/or joints of the bridge, not just the surface.

[Birdsfan]

At least 8 to 10 cars are believed to be in the river.

[Birdsfan]

I don't know if I heard correctly or not as I was playing with the little one and trying to listen, but I think they were also working on the structure and/or joints of the bridge, not just the surface.

Yes, they were. And there was some pile driving work scheduled to be going on.

[Son of Bear]

^So they were doing some foundation (bridge pier) rework? Link?

[Birdsfan]

^So they were doing some foundation (bridge pier) rework? Link?

Weekly Update

 

For the week of July 30, 2007

 

General Updates

 

I-35W Bridge Work at Minnehaha Parkway

 

Work on the I-35W bridge over Minnehaha Creek and Minnehaha Parkway continues; weather

permitting. Daytime pile driving will occur for temporary widening of the existing northbound I-

35W bridge; excess noise may be associated with the activities. Starting Monday, August 6,

2007, Minnehaha Parkway will be closed for three weeks. (see Neighborhood Updates for more

information).

 

LINK

[Birdsfan]

The lengthy area of collapse might be explained by a phenomenon called "aereolastic flutter".

 

Any engineers in the house?

 

Here's some basic info on this "flutter" effect:

 

Flutter is a self-starting vibration that occurs when a lifting surface bends under aerodynamic load. Once the load reduces, the deflection also reduces, restoring the original shape, which restores the original load and starts the cycle again. In extreme cases the elasticity of the structure means that when the load is reduced the structure springs back so far that it overshoots and causes a new aerodynamic load in the opposite direction to the original. Even changing the mass distribution of an aircraft or the stiffness of one component can induce flutter in an apparently unrelated aerodynamic component.

 

At its mildest this can appear as a "buzz" in the aircraft structure, but at its most violent it can develop uncontrollably with great speed and cause serious damage to or the destruction of the aircraft.

 

Flutter can also occur on structures other than aircraft. One famous example of flutter phenomena is the Tacoma Narrows Bridge.

[oldrambler]

Prayers go out for all involved and for the rescue workers that are working the scene. Divers are in the water now and are expected to be in the water overnight. 6 confirmed dead, much more expected -per:Mayor of Minneapollis. As many as 50 cars were on the bridge at time of collapse.It was told that the work going on at the bridge was not structural in nature. This is just terrible, very tragic. May God bless everyone involved (Victims, Emergency workers, Police, Doctors, Hospital workers ........all involved) and the famlies of these people.

 

Was also reported that there were no signs that this tragedy had to do with terroism.

[HOMELESS CAMEL]

The lengthy area of collapse might be explained by a phenomenon called "aereolastic flutter".

 

Any engineers in the house?

 

Here's some basic info on this "flutter" effect:

 

Flutter is a self-starting vibration that occurs when a lifting surface bends under aerodynamic load. Once the load reduces, the deflection also reduces, restoring the original shape, which restores the original load and starts the cycle again. In extreme cases the elasticity of the structure means that when the load is reduced the structure springs back so far that it overshoots and causes a new aerodynamic load in the opposite direction to the original. Even changing the mass distribution of an aircraft or the stiffness of one component can induce flutter in an apparently unrelated aerodynamic component.

 

At its mildest this can appear as a "buzz" in the aircraft structure, but at its most violent it can develop uncontrollably with great speed and cause serious damage to or the destruction of the aircraft.

 

Flutter can also occur on structures other than aircraft. One famous example of flutter phenomena is the Tacoma Narrows Bridge.

 

I think Mythbusters actually covered something very similar to this a while back.

[KY Thorobred]

At least 7 Dead, 60 Injured according to WLEX