I-35 Bridge: "We're taking it out."

[DeHannen]

I am watching the coverage on the bridge collapse, more specifically the accounts of all the people saying they heard "explosions" and loud bangs prior to the collapse. One person reported "it was like a bomb going off". This should be a great exercise in watching how lay people describe a structural collapse. I don't want to turn this into another conspiracy thread (please don't). But the reaction of the locals provide interesting descriptions of what clearly (at this point) is a structural failure.

BTW, it's early and I can only see the pics from the TV, but based on the fact the concrete columns appeared intact, this looks like the main span of the bridge had a bottom chord joint failure, the remaining top chords went into tension and pulled the adjacent sections of bridge off of their supports. The NTHB will send their team in, and I imagine ASCE will get a team together. Condolences go out to all the people killed in this tragedy.

[mighty mouth]

Well...the news said this morning they had ruled out terrorism....so it seems pretty unlikely that there was any kind of explosion.

[DeHannen]

Mods can you move this to Wells, I didn't mean to have this on the main board.

[BrodieMSU]

structural steel can make a loud popping noise, like a bang, when it fails, so it doesnt surprise me that some peope think it was a bomb.

what does make it weird is that it was inspected annually, here in FL, FDOT requires bridges to be inspected every 2 years. Im sure the inspection reports from the DOT will be available at some point online, will be interesting

[Toolman]

Have any of you heard what a cement structure failling sounds like? This notion that everything breaking sounds like a bomb is stupid.

[TheDoctorIsIn]

yeah, i'd imagine big bridges don't fall silently, so the loud noises aren't suprising

[Eli Broad]

Originally Posted by DeHannen

Mods can you move this to Wells, I didn't mean to have this on the main board.

Wells Hall sucks. I thought you said you didn't want a big conspiracy thread.

[HawkeyeCheesehead]

Originally Posted by Hecklers

Do you have a lisp?

[Statepug]

Originally Posted by Hecklers

there is video of it from some security camera. No explosions.

What about all the dust and debris getting ejected to the sides? Must have been a couple of hundred feet.

[chachi]

Originally Posted by DeHannen

I am watching the coverage on the bridge collapse, more specifically the accounts of all the people saying they heard "explosions" and loud bangs prior to the collapse. One person reported "it was like a bomb going off". This should be a great exercise in watching how lay people describe a structural collapse. I don't want to turn this into another conspiracy thread (please don't). But the reaction of the locals provide interesting descriptions of what clearly (at this point) is a structural failure.

BTW, it's early and I can only see the pics from the TV, but based on the fact the concrete columns appeared intact, this looks like the main span of the bridge had a bottom chord joint failure, the remaining top chords went into tension and pulled the adjacent sections of bridge off of their supports. The NTHB will send their team in, and I imagine ASCE will get a team together. Condolences go out to all the people killed in this tragedy.

This bridge... 35' off of the water took 4 seconds to collapse... WTC 1 and 2... .9 and 11 seconds respectively (NIST).

What you describe is a "progressive collapse"... funny how long it took?

There is your conspiracy angle.

[Lochgelly]

Originally Posted by DeHannen

I am watching the coverage on the bridge collapse, more specifically the accounts of all the people saying they heard "explosions" and loud bangs prior to the collapse. One person reported "it was like a bomb going off". This should be a great exercise in watching how lay people describe a structural collapse. I don't want to turn this into another conspiracy thread (please don't). But the reaction of the locals provide interesting descriptions of what clearly (at this point) is a structural failure.

BTW, it's early and I can only see the pics from the TV, but based on the fact the concrete columns appeared intact, this looks like the main span of the bridge had a bottom chord joint failure, the remaining top chords went into tension and pulled the adjacent sections of bridge off of their supports. The NTHB will send their team in, and I imagine ASCE will get a team together. Condolences go out to all the people killed in this tragedy.

I watched ALOT of coverage and I never heard one single person say they heard explosions prior to the collapse...if your comparing witness reactions to 911 with the intent of somehow proving a "witness reaction thoery" in order to bolster your 911 "official story" theory...you will be disappointed. Because almost to a T, the witnesses said they heard a jack hammerring noise, a sudden shaking...and then the collapse.

Unlike many, many witnesses on 911 who stated they heard explosions in the basement and then popping sounds all up and down the building before the collapse. Don't get me wrong..I still believe the "official theory"...well except for Building 7...but you'll have to go to Wells to see that analysis....

Could the bridge collapse been terrorism? Well it is still possible...but it sounds unlikely.

[Statepug]

Originally Posted by Hecklers

Result of the bridge falling into the Mississippi River I suppose. I guarantee you know more about this kind of stuff than I do - I just watched the video on CNN.com's main page and the bridge just falls straight down.

It was sort of a tongue in cheek reference to some unnamed threads on the other board, I don't want this to turn into something like that. One of the engineers from here is just north of Minneapolis for the week, I'm pretty sure he will drive down and take a look at it, hopefully get some pictures. On another note, my son's wife works pretty close to that bridge and usually takes it home from work, but took a different route due to the construction. My son is on a job about 400 miles away and was freaking out when he heard about it and couldn't get a hold of her. About 2 hours later she finally got through on her cell phone, couldn't before that due to the cell phone traffic. Hugh sigh of relief from him and from our house.

[Leeroy Jenkins]

Originally Posted by Toolman

Have any of you heard what a cement structure failling sounds like? This notion that everything breaking sounds like a bomb is stupid.

Have you ever heard structural steel or reinforced concrete fail? Or how about a mass that large hitting a body of water? I bet you would be surprised how loud it actually is.

[Dr. Strangelove]

Did someone say, "Pull it"?

[BrodieMSU]

Originally Posted by chachi

This bridge... 35' off of the water took 4 seconds to collapse... WTC 1 and 2... .9 and 11 seconds respectively (NIST).

What you describe is a "progressive collapse"... funny how long it took?

There is your conspiracy angle.

If you are trying to compare the collapsing time of a bridge and a tower building, its completely offbase. Those are two completely different structures, with two completely difference failure mechanisms.

[lars]

But what about all the witnesses that 'heard explosions'

It was a govt conspiracy..the bridge was clearly a controlled demolition.


Signed

Roundhead, Chachi and Al Czervik

[Al Czervik]

4/29truth.com » Blog Archive » I-35W Bridge Collapse Proves 4/29 Sabotage

[chachi]

Originally Posted by lars

But what about all the witnesses that 'heard explosions'

It was a govt conspiracy..the bridge was clearly a controlled demolition.


Signed

Roundhead, Chachi and Al Czervik

The low level explosions in WTC 1 and 2 blew out the first floors hard enough to dislodge the marble panels and almost all windows (there is video of this), etc, smoke can be seen rising form the base of the towers pre-collaspe in many videos, the eye witnesses reporting these explosions were first responders (firemen who have heard all sorts of explosions) in and around the buildings.

Why not respond to the fact that the bridge, in a gravity driven progressive collapse, with no resistance/structure to impede it below, took 4 seconds to collapse to the water and WTC 1 and 2 took 11 and 9 seconds.

But, twist it however you like.

You have never been big on facts, logic or education.

[chachi]

Originally Posted by BrodieMSU

If you are trying to compare the collapsing time of a bridge and a tower building, its completely offbase. Those are two completely different structures, with two completely difference failure mechanisms.

A bridge with essentially TWO supports takes 4 seconds to fail because ONE truss was lost and progressed to the others... Progressive collapse, far less supports, smaller safety factor due to age. Why the delay? Why not instant failure like the THREE WTC towers? Why not ignore the intact resistance like in the WTC?

WTC towers avg. 10 seconds to collapse (NIST) because of (officially) a truss failed overloading other trusses and causing them to fail, the causing all the columns to fail even in 70 untouched floors and causing global collapse in < 11 seconds in both cases.

IDK... seems like the bridge should have collapsed in < 1 second per. 9/11 gravity magic.

[Statepug]

Originally Posted by chachi

You have never been big on facts, logic or education.

way to get your point across ********

[BrodieMSU]

Originally Posted by chachi

A bridge with essentially TWO supports takes 4 seconds to fail because ONE truss was lost and progressed to the others... Progressive collapse, far less supports, smaller safety factor due to age. Why the delay? Why not instant failure like the THREE WTC towers? Why not ignore the intact resistance like in the WTC?

WTC towers avg. 10 seconds to collapse (NIST) because of (officially) a truss failed overloading other trusses and causing them to fail, the causing all the columns to fail even in 70 untouched floors and causing global collapse in < 11 seconds in both cases.

IDK... seems like the bridge should have collapsed in < 1 second per. 9/11 gravity magic.

this is so sad, you have no idea what you are talking about

[chachi]

Originally Posted by BrodieMSU

this is so sad, you have no idea what you are talking about

Another solid, fact filled, refutation based on evidence and logic. Kudos to you Brodie. Way to bring it strong.

[BrodieMSU]

Originally Posted by chachi

Another solid, fact filled, refutation based on evidence and logic. Kudos to you Brodie. Way to bring it strong.

would you rather i state "progression" or "progressive" as many times as i possibly can in one reply? i dont know what your background is in structural engineering, but i know you dont know what you are talking about. its ridiculous to compare a building and a bridge in failure modes. i know this because i actually am a structural engineer.


anyways, in non-idiotic news, heres the latest (and most likely):


Cracking, Vibration May Have Contributed to Collapse, Former NTSB Chairman Says

Star Tribune, Minneapolis - Investigators looking into the cause of the Interstate Hwy. 35W bridge collapse are likely to focus on two primary causes -- vibration and fatigue cracking, the former chairman of the National Transportation Safety Board said in an interview early this morning.
Jim Burnett said they should look at whether vibration from the construction work contributed to the collapse, or whether a train that was under the bridge at the time may have been moving, contributing vibration to the bridge.
"Vibration is one of things that cause cracking to propagate," he said. "They will be looking at that."
Burnett, who is in town for a Republican National Committee meeting, was watching the scene at 5 a.m. with other onlookers at the University Avenue SE. northbound entrance.
He also said he was intrigued by a 2001 University of Minnesota study that found signs of "fatigue cracking" in the bridge supports, though he noted that a later report apparently concluded that the bridge was in no immediate danger and did not need major repairs.
"I think that decision is going to come under new scrutiny," he said.


essentially, this was a fatigue crack in a fracture critical member