Don't know if this video has been posted. Straight view on dash cam video where you can see the break happen on the left hand side where they were working
There’s another video that shows up after the bridge collapse that explains what probably happened. They screwed the pooch moving the bridge by moving one of the creeper pillars and didn’t use the original placements and load spreaders. Then one of the tensioners catastrophically failed as they were trying to tighten it. The damage had been done earlier by the moving but the instant total collapse was due to the tensioner failure. Everyone involved in the attempted tightening of the tensioner to correct the problem while traffic was allowed under the span should be charged with negligent homicide. https://m.youtube.com/watch?v=ioC61...8F49spAz023VZXSiRJIOjDISbxNjywwZPeLH1VjA
The video is really annoying but he finally gets to the point and is thoroughly convincing to me. The tensioner hanging way out and straight after his hydraulic cylinder and all thread demonstration is had to argue with.
Last edited by Daveinjax; 03/18/18.
‘TO LEARN WHO RULES OVER YOU, SIMPLY FIND OUT WHO YOU ARE NOT ALLOWED TO CRITICIZE’
Conspiracy theorists are the ones who see it all coming…
Maybe its just me, but it would seem prudent to detour traffic if you are stress testing a bridge. The keywords are stress and test.
They weren’t “stress testing “ . They were trying to tighten one of the tensioners that wasn’t holding tension like it should. Apparently nobody stepped back and acknowledged that they had already destroyed the bridge during the move and were trying to treat the symptoms. The negligence was criminal imo. The bridge was already cracking up and there was plenty of warning. Cracks and loud bursting sounds had been seen and heard already but they allowed traffic under the bridge anyway and then tried some desperate remediation while people were under the bridge. The crew running that operation were buying their stupid pills by the gallon jug full !
‘TO LEARN WHO RULES OVER YOU, SIMPLY FIND OUT WHO YOU ARE NOT ALLOWED TO CRITICIZE’
Conspiracy theorists are the ones who see it all coming…
Looking at the dashcam collapse video and one of the photos with the tensioner jack and tendon sticking out of the top of the rubble, my view has evolved to thinking that they were pulling on the tensioner tendon in the web member (diagonal member) farthest south (closest to the break). At normal bridge loading, the web member in question is under compression, and is responsible for transmitting nearly 50% of the bridge's weight to the support pier.
It's not that hard to spitball the load of the member in question with some rough assumptions. End load (500t) is about half of total bridge weight (950t), web member about 30° off horizontal (eyeballed from photos), vertical component of gravity load is 500t, load in the member is all axial, so total axial gravity load is 500t/(sin30) = 1000t = 2000kip = 2 million pounds...the post tensioning device adds to that. It's a big tendon, judging by how far it sticks out of the hole with the tensioning ram still hanging cantilevered to its end! Not unreasonable to assume multiple hundreds of thousands of pounds of tension member load added to the gravity load.
When the bridge collapses in the video, the web member in question collapses (shortens), and the upper and lower bridge chords fold where their sudden bending load is highest.
If any of what's posted above is true regarding misplaced transport supports, damage to or near the member in question, relaxing of tensioner within the member in question during the move and placement, noise before and after placement, etc., and they went ahead anyway with in-place tensioning of the member in question (planned or remedial) without blocking traffic, then folks are going to jail. Galactic negligence. Even if there wasn't evidence of damage, that work should have been done at night, with traffic blocked and access limited (NO PERSONNEL ON OR NEAR THE BRIDGE), at the very least. It's not hard to run tensioning equipment remotely...extend hydraulic hoses from the safely-located power pack to the ram, monitor pressure (which correlates directly to pull force) at the power pack, and measure elongation via manlift when tensioning is paused. OSHA is going to have a field day with this.
Looking at the dashcam collapse video and one of the photos with the tensioner jack and tendon sticking out of the top of the rubble, my view has evolved to thinking that they were pulling on the tensioner tendon in the web member (diagonal member) farthest south (closest to the break). At normal bridge loading, the web member in question is under compression, and is responsible for transmitting nearly 50% of the bridge's weight to the support pier.
It's not that hard to spitball the load of the member in question with some rough assumptions. End load (500t) is about half of total bridge weight (950t), web member about 30° off horizontal (eyeballed from photos), vertical component of gravity load is 500t, load in the member is all axial, so total axial gravity load is 500t/(sin30) = 1000t = 2000kip = 2 million pounds...the post tensioning device adds to that. It's a big tendon, judging by how far it sticks out of the hole with the tensioning ram still hanging cantilevered to its end! Not unreasonable to assume multiple hundreds of thousands of pounds of tension member load added to the gravity load.
When the bridge collapses in the video, the web member in question collapses (shortens), and the upper and lower bridge chords fold where their sudden bending load is highest.
If any of what's posted above is true regarding misplaced transport supports, damage to or near the member in question, relaxing of tensioner within the member in question during the move and placement, noise before and after placement, etc., and they went ahead anyway with in-place tensioning of the member in question (planned or remedial) without blocking traffic, then folks are going to jail. Galactic negligence. Even if there wasn't evidence of damage, that work should have been done at night, with traffic blocked and access limited (NO PERSONNEL ON OR NEAR THE BRIDGE), at the very least. It's not hard to run tensioning equipment remotely...extend hydraulic hoses from the safely-located power pack to the ram, monitor pressure (which correlates directly to pull force) at the power pack, and measure elongation via manlift when tensioning is paused. OSHA is going to have a field day with this.
Now that's speculation run amok!
I don’t think it’s run amok and I believe there will be people going to jail for criminal negligence. With the little bit we know for sure already the fact that there was anyone allowed under or on that span is criminal negligence on the part of the construction company management.
Last edited by Daveinjax; 03/18/18.
‘TO LEARN WHO RULES OVER YOU, SIMPLY FIND OUT WHO YOU ARE NOT ALLOWED TO CRITICIZE’
Conspiracy theorists are the ones who see it all coming…
Just saw on the local news that the company that designed this bridge is also the one that was hired to do the new harbor bridge here, which they have started construction on......
God bless Texas----------------------- Old 300 I will remain what i am until the day I die- A HUNTER......Sitting Bull Its not how you pick the booger.. but where you put it !! Roger V Hunter
Just saw on the local news that the company that designed this bridge is also the one that was hired to do the new harbor bridge here, which they have started construction on......
You might wanna find a permanent detour Rog.
Paul
"I'd rather see a sermon than hear a sermon".... D.A.D.
Trump Won!, Sandmann Won!, Rittenhouse Won!, Suck it Liberal Fuuktards.
Would it have been too simple, and therefore much less expensive, to have just built a basic pedestrian bridge that serves the purpose without trying to turn it into a massive "statement" structure complete with lounging area with seating, desk surfaces, potted plants, benches, and other extraneous stuff shown in the concept drawing? there are bound to be dozens of pedestrian bridges build by both government and civilian interests that have stood the test of time that were designed without computers, and built with basic bridge construction materials and techniques by a competent contractor. This situation reflects one of my favorite sayings that I find myself saying more often all the time; "why does everything have to be so damn complicated?"
Increasing my post count so people will buy stuff from me
immature, but that's not the "progressive" way! It can't be done like that.
Ed
"Not in an open forum, where truth has less value than opinions, where all opinions are equally welcome regardless of their origins, rationale, inanity, or truth, where opinions are neither of equal value nor decisive." Ken Howell
Would it have been too simple, and therefore much less expensive, to have just built a basic pedestrian bridge that serves the purpose without trying to turn it into a massive "statement" structure complete with lounging area with seating, desk surfaces, potted plants, benches, and other extraneous stuff shown in the concept drawing? there are bound to be dozens of pedestrian bridges build by both government and civilian interests that have stood the test of time that were designed without computers, and built with basic bridge construction materials and techniques by a competent contractor. This situation reflects one of my favorite sayings that I find myself saying more often all the time; "why does everything have to be so damn complicated?"
Then it would not be trendy and cutting edge not even 2 miles from where I sit the NCDOT placed 2 Metal Arches over 4 lanes of highway 52 that cost 2 million dollars. They serve exactly what purpose?
not even 2 miles from where I sit the NCDOT placed 2 Metal Arches over 4 lanes of highway 52 that cost 2 million dollars. They serve exactly what purpose?