Posted on 03/15/2018 11:32:16 AM PDT by Red Badger
MIAMI (CBSMiami) — Florida International University’s massive new pedestrian bridge collapsed Thursday afternoon in West Miami-Dade.
The bridge, located at 109th Ave and 8th Street, collapsed on a number of cars.
There are reports of numerous people injured in the collapse. At least one person was taken as a trauma alert to the hospital, according to Miami-Dade Fire Rescue.
The 950-ton bridge went up on Saturday. It was then lowered into its final position, just west of 109th Avenue that day.
The main span was built next to Southwest 8th Street.
174 feet, but I don’t know if that’s the entire bridge or just this span. I just found out that this was to be a suspension bridge upon completion. The cables weren’t in place yet.
Thank God for that much. Not opened to foot traffic? Miracle.
Failure analysis ping.
Could that crane have been tightening something...
ABC News saying that a stress test was taking place on the bridge at the time of the collapse.
Concrete does not reach maximum strength until sometime after pouring:
One criteria used is the 28-day test strength as the allowable stress value for the design. There are high early strength concretes that can give you quicker curing times but 28 days is the norm.For many purposes, concrete can be used or loaded at earlier times depending on circumstances. Normal concrete will get about two thirds of its strength in just 7 days so many times that is the criteria for some uses.
How long does it take freshly poured concrete to cure to full strength?
Wouldn’t it better if they protested on the football field for 32.174 minutes?
The bridge collapsed during a stress test!!! With traffic underneath. 3rd World Construction and Incompetence.
Been trying to get onto the FIGG website but looks like it may be offline - wondering why. /s
I'm no bridge building expert, but I'd think the suspension would have to be in place before attempting to place an entire section of bridge, right?
Probably some foreigner... We Americans are not qualified to build our bridges nowadays... Just ask the government, they'll tell'ya...
The reporting is very misleading. As I read it what was innovative was use of Self Propelled Modular Transport. This was simply placement of a span cast (in this case) beside the roadway instead of over it to reduce danger during construction and simplify the construction of the concrete span.Mobile heavy lift units then placed the completed span on its permanent supports (apparently last Saturday).
Looking at the pictures I would guess either failure of the anchors on the prestressing cables in the unit, bad design, substandard concrete or bad placement of the concrete (insufficient vibration?)any of these possible especially with the widespread use of illegal labor in the industry in So. Florida.
Looks like it failed the test....................
The slump can be variable. I’ve designed concrete mixes with zero inches of slump, but those were for airport concrete pavements. Zero slump mix is very hard to work, flow, and finish.
Eyep...before a mixer even starts pouring the concrete that test is done
on every truck load....
“ABC News saying that a stress test was taking place on the bridge at the time of the collapse.”
They did a stress test with a bunch of cars full of people under the bridge?
Here is another image of the project as it would have looked.
Looked like some sort of open web joist type structure, constructed off site and brought into place. Sometimes designed turnkey by a specialty subcontractor. Oftentimes relying on software to size the members and connections. Places to look - value engineering to reduce costs and perhaps the qualifications of the general contractor.
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