Boston bridge construction
AJ Walden posted four photos with the comment:
Big thanks to Scott gmk6300l and Steve gmk6400l from Maxim Crane out of Indianapolis for setting a 190 foot long 200,000 lbs pedestrian bridge in Kokomo ,Indiana for me on 3/28/18. It was a long day and both were great ops to work with and did a he'll of a job for me.Dennis DeBruler Was this truss built along side the road with the lattice boom crane and then these two Groves swung it in place. In the last photo, what is the boom under the bridge doing?
AJ Walden Yes it's was built on the side of the road. The last photo is the 450 breaking down after the bridge was set.
AJ Walden 6 ranging in length from 56 feet to 67 feet and 29k to 35k in weight per piece would have been nice to of had more room but it was a fun build.
This 200', $2m bridge is obviously a concrete truss bridge with an arch added for additional strength.
A drone video shows them adding the final piece to the truss. It also shows how it looked after it was installed. They could not capture the lift of the whole truss because that was done at night, as AJ's photos show.
(Update: some information from a NTSB video)
I haven't written about the 950-ton Florida International University Bridge because it collapsed on 3/15/2018 just a few days after it was moved into position over the highway. Thus it has been all over the news. Now when you do a Google search, most of the entries are about lawsuits.
They pulled four bodies out of the rubble the day of the crash, and I see the death toll is now up to six. [CBS] I have seen dashcam videos of the collapse. It was a catastrophic failure. The truss members were post-tensioned with two rods each. They were changing the stress on the rods after the move to compensate for the change between the moving equipment supporting the truss away from the edges and the abutments supporting the truss at the edges. Some reports said they were doing a stress test. But evidently that had been completed before the collapse. Reports indicated that they did not stop the traffic for stress testing, with the implication that you don't do stress testing over live traffic.
A pylon with cable stays was supposed to be added. But that was to stiffen the truss. It was not supposed to be needed to support the truss. FIU was bragging about the innovative nature of the bridge design.
|From Kokomo Tribune|
|David Mack tweet from Kokomo Tribune|
|David Mack tweet from Kokomo Tribune|
I watched blancolirio's channel concerning the Orville Dam disaster. I learned he has good content, so when I saw he is covering the FIU collapse, I'll try to catch them.
I set through 23 minutes of this video before I gave up watching because he was basically repeating himself over and over. One thing I did learn is that only four of the eight post-tension ducts in the canopy had been used. When I found another video from this guy, I didn't even look at it because it became obvious from the comments that he should be ignored. I'll patiently wait for more videos from blancolirio.
At this location in a video, I learned that one of the bolts tightened too easily. That indicates the steel tendon had transitioned from its elastic stage to its plastic stage. That is, it had lost its strength. They knew this loose nut was bad news because they discussed it. But they evidently shrugged their shoulders and continued to pull the tendon until it broke. They did not clear the traffic under the bridge even though they had evidence that a tendon had more strain than it could handle.
[Lifting a 132', 242,000 pound span into place to cross the five MBTA and Amtrak rail lines that divide the Northeastern University campus (Unfortunately, I could not make the time-lapse video work for me.)]
Dennis DeBruler shared
It looks like a MLC650 to me. The article states: "Such a heavy piece [242,000 pounds] required one of the largest cranes on the East Coast to lift it."
Richard Himelrick It is a 650 was by there the other day it really stood out against the skyline.
Dennis DeBruler shared this link in a Manitowoc group.
Richard Himelrick It is a 650 was by there the other day it realy stood out against the skyline.
Sarah Wolfe I swear every project article calls every crawler crane the biggest in the state/on the coast.
Marty Jr Jackson posted two photos as comments:
[It looks like there are mats extended towards the bridge spans. So it had to walk the load as well as swing it about 180 degrees.]