I debated whether to place this here or in "Current Events...". I think it qualifies as technology, so I put it here. The mods can of course move it if they think it's appropriate.
This project took place over the weekend near where I live.
General description here:
Video here
The mission broadly: Demolish old bridge and move prefabricated new bridge into position in a weekend. specifically 10 PM Friday to 5:30 AM Monday. The project was actually completed ahead of schedule.
More detail of tasks:
This is roughly chronlogical order, but there was a lot of overlap, with two or three things happening at once the whole time.
Remove concrete barriers from median and sides of highway.
Cover the highway with dirt. This was done, in combination with steel plates (more later) in order to prevent the pavement from being damaged by the high wheel loads during bridge movement. Most of the dirt was taken from an embankment between I-70 and the eastbound off ramp, though it appeared that some was trucked in from elsewhere. I'm not sure exactly how deep the layer of dirt placed on the highway was. At a guess I would say 4-6 inches.
Demolish old bridge, break up rubble, separate re-bar from concrete for recycling, and haul it all away.
Place steel plates on top of dirt in path used for wheels of bridge transport.
Roll bridge from construction location onto highway, rotate it 180 degrees (the bridge was asymmetrical, hourglass shaped (to accommodate part roundabouts), with one end bigger than the other. Apparently it would only fit in the area where it was constructed backwards, necessitating the rotation.) The area where it was rotated was entirely covered with steel plates. Steel plates were placed only on the wheel track for the rest of the path (about 800 feet according to CDOT website).
Set bridge in place.
Remove transport equipment from under bridge and move off highway.
Remove steel plates.
Remove dirt from highway and put it back into embankment.
Reset concrete barriers.
I spent probably too much time watching this over the weekend, both on-site and on webcam. The placement of the bridge was originally scheduled for 3:00 AM Sunday, but was complete when I briefly visited the site at 1:00 AM Sunday. When I visited at 7:00 PM Sunday, the project was nearly complete, with only setting of barriers and cleanup of the last of the dirt in progress.
The coordination (I am tempted to say choreography) was truly amazing. In spite of there being an incredible amount of people (I would guess at least 100) and equipment in a fairly small area, I rarely saw anybody get in anybody else's way. Everybody seemed to know exactly what they were doing, as if they demolished and removed bridges every day. The only real miscue of any kind I saw was a couple of the steel plates dropped by the forklift (actually, articulated loaders fitted with forks instead of buckets) operators.
On Saturday morning, during the removal of the debris from the old bridge, I counted 10 excavators in a small area. One was fitted with a jackhammer attachment to break up concrete. Another had a bucket with a "thumb" to grab rebar to remove it from the concrete and load it into trailers. There were at least three articulated loaders, two of which were fitted with forks during the setting the steel plates, a road grader, a couple of vibrating rollers (for compactint the dirt) a backhoe and a "bobcat"(small tracked front end loader), two or three dump trucks, and I have no idea how many semi-trucks, hauling side dump trailers for hauling away concrete, open-top gondola trailers for hauling away rebar, and flatbeds for steel plate and median barriers.
All in all, it was a truly amazing effort.
This project took place over the weekend near where I live.
General description here:
Video here
The mission broadly: Demolish old bridge and move prefabricated new bridge into position in a weekend. specifically 10 PM Friday to 5:30 AM Monday. The project was actually completed ahead of schedule.
More detail of tasks:
This is roughly chronlogical order, but there was a lot of overlap, with two or three things happening at once the whole time.
Remove concrete barriers from median and sides of highway.
Cover the highway with dirt. This was done, in combination with steel plates (more later) in order to prevent the pavement from being damaged by the high wheel loads during bridge movement. Most of the dirt was taken from an embankment between I-70 and the eastbound off ramp, though it appeared that some was trucked in from elsewhere. I'm not sure exactly how deep the layer of dirt placed on the highway was. At a guess I would say 4-6 inches.
Demolish old bridge, break up rubble, separate re-bar from concrete for recycling, and haul it all away.
Place steel plates on top of dirt in path used for wheels of bridge transport.
Roll bridge from construction location onto highway, rotate it 180 degrees (the bridge was asymmetrical, hourglass shaped (to accommodate part roundabouts), with one end bigger than the other. Apparently it would only fit in the area where it was constructed backwards, necessitating the rotation.) The area where it was rotated was entirely covered with steel plates. Steel plates were placed only on the wheel track for the rest of the path (about 800 feet according to CDOT website).
Set bridge in place.
Remove transport equipment from under bridge and move off highway.
Remove steel plates.
Remove dirt from highway and put it back into embankment.
Reset concrete barriers.
I spent probably too much time watching this over the weekend, both on-site and on webcam. The placement of the bridge was originally scheduled for 3:00 AM Sunday, but was complete when I briefly visited the site at 1:00 AM Sunday. When I visited at 7:00 PM Sunday, the project was nearly complete, with only setting of barriers and cleanup of the last of the dirt in progress.
The coordination (I am tempted to say choreography) was truly amazing. In spite of there being an incredible amount of people (I would guess at least 100) and equipment in a fairly small area, I rarely saw anybody get in anybody else's way. Everybody seemed to know exactly what they were doing, as if they demolished and removed bridges every day. The only real miscue of any kind I saw was a couple of the steel plates dropped by the forklift (actually, articulated loaders fitted with forks instead of buckets) operators.
On Saturday morning, during the removal of the debris from the old bridge, I counted 10 excavators in a small area. One was fitted with a jackhammer attachment to break up concrete. Another had a bucket with a "thumb" to grab rebar to remove it from the concrete and load it into trailers. There were at least three articulated loaders, two of which were fitted with forks during the setting the steel plates, a road grader, a couple of vibrating rollers (for compactint the dirt) a backhoe and a "bobcat"(small tracked front end loader), two or three dump trucks, and I have no idea how many semi-trucks, hauling side dump trailers for hauling away concrete, open-top gondola trailers for hauling away rebar, and flatbeds for steel plate and median barriers.
All in all, it was a truly amazing effort.
via JREF Forum http://forums.randi.org/showthread.php?t=262572&goto=newpost
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