china bot posted:

My name is Michael Weston. I used to be a spy, until...*bridge collapses*

IPCRESS posted:

Have they found that the collapse occurred because someone notched the top of the bridge to install a bathtub?

turn off the TV posted:

I can't imagine how difficult it's going to be for the people of miami trying to commute to work tomorrow. I hope they stay strong.

Nerses IV posted:

It's interesting that this bridge had cracking bad enough to pique an engineer's interest

The general rule is if you don't want concrete to crack, don't pour it. So if people start worrying about cracking, it's got to be pretty loving bad, and this thing was already heading up the big slide when the post-tension guys went up to try and save it

e: and then the post tension guys got on the jack, started pulling, saw the needle wasn't moving on the gauge even though the bar was pulling out, went "huh that's weird" and then KERBLAMMO

Panzeh posted:

This is kinda why I suspect it was a repair that might not have gone quite as planned.

You're right about repairs being really hair-raising in monostrand- i look at these procedures and i wonder how the hell they don't tear up a bunch of other cables/rebar when they do it and such. I've seen some procedures that are kinda nuts.

meat police posted:

No one has the balls to say it? Obvious false flag op

let it mellow posted:

oh yeah because u set up a detour for a couple hours

u drooling imbecile

and it only takes a couple hours to perform the tensioning procedure as described earlier by pro engineers itt

u obdurate moron

and of course the whole logistics of setting up a detour, rerouting traffic, managing inspections and whatever ancillary things like video documentation, new stuff, etc also fits in this magic one hour window

u idiot shitfucker

Arrhythmia posted:

This dude is majorly getting worked up because someone suggested that they should have had a detour while loving around with the bridge that killed 8 people lmao.

Fame Douglas posted:

Well, they do have a detour set up now.

cda posted:

Finding out that all the bad politics posters are engineering nerds is unsurprising but still satisfying.

Fame Douglas posted:

Well, they do have a detour set up now.

Prav posted:

if this is what passes for a pedestrian bridge collapse in america i'd hate to see an extraordinary one

Prav posted:

if this is what passes for a pedestrian bridge collapse in america i'd hate to see an extraordinary one

Arrhythmia posted:

This dude is majorly getting worked up because someone suggested that they should have had a detour while loving around with the bridge that killed 8 people lmao.

Raldikuk posted:

I'm the gigantic smoke ring in the sky

Nerses IV posted:

Haha, well... the short answer is, they do

We used to have bandlines that were about 800 feet long, pulled at both ends and at the construction joint in the middle, and if somebody broke one in the second pour (this happened all the time, you see there's floor-to-ceiling windows running along the entire south side of the building............) we'd have to use one of these



These things were my loving enemy

FuturePastNow posted:

https://twitter.com/ScottGustin/status/974834804821807104

Arrhythmia posted:

This dude is majorly getting worked up because someone suggested that they should have had a detour while loving around with the bridge that killed 8 people lmao.

Supreme Allah posted:

Am I understanding correctly that what's happened is this




But that black (rubber?) thingy is supposed to make it seem as if nothing ever happened

Samuel L. ACKSYN posted:

Samuel L. ACKSYN posted:

Samuel L. ACKSYN posted:

Prav posted:

if this is what passes for a pedestrian bridge collapse in america i'd hate to see an extraordinary one

Samuel L. ACKSYN posted:

Samuel L. ACKSYN posted:

FuturePastNow posted:

https://twitter.com/ScottGustin/status/974834804821807104

EX250 Type R posted:

Is that a person standing on it on the left side?

FuturePastNow posted:

https://twitter.com/ScottGustin/status/974834804821807104

Supreme Allah posted:

Nerses IV posted:

This is pretty much what's happening, yeah. You pull on both of those cable tails and the (steel) splice coupler holds them both in place, making the thing act like a single tendon under tension. It's scary as hell because they're getting pulled at weird angles and at some point, one half of the cable will be under tension, and the other half won't be, so you're sitting there loving around with something that wants to explode, way outside the preferred methods for stressing a cable.

That cable was supposed to be stressed to 33 kips, at which point it would back off to around 28 kips while the little gripping wedges inside the coupler (or the anchor, on an undamaged cable) engage and keep the cable from retracting any farther. We didn't get anywhere near that on that one because it was INCREDIBLY grumpy when we started pulling on it (wedge failure that sent glowing bits of steel flying everywhere type of grumpy), so we pretty much got some decent tension and got the gently caress away from it. This whole stressing procedure happened on a Saturday, and we told anyone working on that floor or the one below to take a break since that cable runs the entire length of the building.

I guess the PT guys working on the bridge had to do it in the middle of the day with a bunch of cars beneath them because, well, they don't call it Accelerated Bridge Construction for nothin'

Panzeh posted:

My company used a different kind of coupler for repairs which was just a cylinder where you put in cable from each direction and it acted like the Chinese finger trap.