[Blue_Nose]

Here's something people might find interesting. I attended the installation of a prefabricated bridge this morning.

The key thing is that this is not a Bailey Bridge - this is one half of the permanent bridge which will replace the existing steel bridge you see on the right. This half will be used as a bypass until the existing bridge is removed and the abutments are modified. Then, a second half will be placed in the location of the steel bridge, and the first half will be moved over, forming a double lane span.

I won't get into the details, but it's actually wrapped entirely in fibreglass. The two sections are fabricated in a shop and transported to the site, where they're fastened together and rails, etc, are added.

That's me you'll hear talking about the spreader bar in the second video.

[youtube]http://www.youtube.com/watch?v=52BTNGG5ljY[/youtube]
[youtube]http://www.youtube.com/watch?v=jM8rwvioP5I[/youtube]
[youtube]http://www.youtube.com/watch?v=FHXSHVsCJjg[/youtube]
[youtube]http://www.youtube.com/watch?v=isrmV9VpCgo[/youtube]

[Wullu]

Good stuff BN. Where about was that? Looks like a replacement for one of NS's infamous single lane bridges......

Only the first two vids will load for me though...

[ziggy]

cant load any of them right now(down to 5mbps) but will they work in -50 weather? Their putting in minimum 8 bridges here in nunavut this winter and half are bailey's. prefab and shipped by barge is the only way to get them here. just curious.

[Blue_Nose]

Wullu wrote:

Good stuff BN. Where about was that? Looks like a replacement for one of NS's infamous single lane bridges......

Yep - one of thousands of bridges that need to be replaced in the Maritimes, and across Canada. Couldn't have been in really bad condition, though, since they were driving the excavator back and forth all morning.

Neat thing about this design is that that section will be accepting traffic by now, and was only put in place this morning. Most bridge installations bung up traffic for at least a day or two... this one, a few hours.

ziggy wrote:

will they work in -50 weather?

Can't say for sure - they aren't temporary, though, so they aren't really a bailey substitute.

[Regina]

That was pretty cool. Although I must admit I thought I was going to see something fall on someone.....................or at least somebody getting a shot in the nuts with an air nailer. The "Net Man" would have posted one like that.

[Blue_Nose]

Nope, nothing fell - except a rag that was wrapped around one of the cross braces.

Actually, I was pretty sure there were going to be a lot of problems when they hoisted it up and the straps weren't centred properly - for some reason, they continued to raise it, and it looked like the whole thing was going to slip from the straps and crash into the truck cab. Luckily, they let it back down and readjusted.

[Blue_Nose]

Another bridge going in today - this one is a Pedestrian Bridge in Dartmouth.

Hopefully I'll get some more videos - this one is quite a bit different!

[RUEZ]

I'm not sure if it's the same thing but I just watched something on the Discovery channel about these steel bridges with fiberglass and whatnot. They were doing the story because of what happened with the overpass in Laval. Interesting stuff. Looks like the same bridge as in the video's.

[Arctic_Menace]

Cool stuff, BN!

[Blue_Nose]

What happened to the videos from the pedestrian bridge, you might ask. Well, it took me longer than I had expected to get to the site, and by the time I got there, 20 minutes late, it was already in place!! Apparently it took them 15 minutes from the back of the flatbed to in place. Even more amazing because of the fact it was fixed to the abutments by very precise pin connections.

Anyway, I was to the second portion of the installation of the bridge from the videos above - these are very similar, so not terrible exciting.

Also, since it was 4 below, they weren't able to join the two modules that day. They had to wait until the temperature was a little higher so the epoxy would set properly.

[youtube]http://www.youtube.com/watch?v=jBBLuwwaxEg[/youtube]
[youtube]http://www.youtube.com/watch?v=J5cguKbUYWI[/youtube][youtube]http://www.youtube.com/watch?v=ZKsxKpWSwZc[/youtube][youtube]http://www.youtube.com/watch?v=pzSQkShvaQM[/youtube][youtube]http://www.youtube.com/watch?v=wSdIxnLd64E[/youtube]

[Blue_Nose]

Something perhaps a little more interesting, though not a video: inside the Confederation Bridge. It's actually quite neat inside there, though the novelty wear off awfully quickly.

Here's one of the better shots I got - those things that look like pipes going in every direction are actually post-tensioning cables.

[Blue_Nose]

Some photos of the pedestrian bridge.

[SprCForr]

Very nice! Thanks for the video. Bailey (or ACCROW) it is definately not!

I'm curious about the trouble finding the centre of gravity when lifting the section. Being that it was designed from the get go as a prefab section, why wouldn't the makers allow for the proper placement to lift it? The prefab bridge equivalent of a lifting eye? Are the sections a standard dimension and is it a matter of keep adding on until the gap is bridged? Yes indeed, very nice kit!

FWIW, It's about time the civil side started taking time into account!

[Blue_Nose]

SprCForr wrote:

Very nice! Thanks for the video. Bailey (or ACCROW) it is definately not!

It's not uncommon here for people to use Baileys as a replacement and end up just leaving them there - I don't know a whole lot about them, but I'm pretty sure they aren't designed for long term use.

SprCForr wrote:

I'm curious about the trouble finding the centre of gravity when lifting the section. Being that it was designed from the get go as a prefab section, why wouldn't the makers allow for the proper placement to lift it? The prefab bridge equivalent of a lifting eye? Are the sections a standard dimension and is it a matter of keep adding on until the gap is bridged? Yes indeed, very nice kit!

I have no idea why it was a problem during that first lift - the whole thing is pretty uniform, so it's a simple matter of measuring the same distance from each end, which they did, but apparently not close enough.

They don't want to use lifting eyes, or something actually built into the bridge, because anything that has to penetrate the fibreglass layer just adds another potential leakage point, therefore another pain in the ass for the people in the shop.

Each bridge is designed specifically for the site, though the basic properties stay the same. We're limited by the weight of each component, though, and those component (50 tons) were about the heaviest the cranes we use can handle. Part of my involvement is to come up with lighter and more "innovative" solutions to the weight limitations.

[Blue_Nose]

New Video!!!

This is completely different - nothing to do with the bridges or my own work. I have some videos of testing I did (busting components of the bridges above), but I'm going to have to edit them or something, because they're fairly drawn out.

This is from a concrete pour we did today as part of a concrete beam design competition (I'm not involved in the competition, just assisting those who are)... We used self-consolidating concrete (SCC), which requires no vibration, and is almost self-leveling. Despite being so simple to pour, the chemicals used to obtain such high fluidity are almost as expensive as the concrete itself.

When I did this project ("back in my day..."), we used regular concrete, shovelled by hand from wheelbarrows, vibrating and rodding the whole time. It's a lot more labour intensive, and took about three times longer. The only downside this year is that using the SCC let the students sit back and take pictures, instead of getting dirty!

It's a bit hard to see at first, but the camera is looking inside the formwork of a concrete beam, and you'll see the concrete flow around all the rebar.

[youtube]http://www.youtube.com/watch?v=FfVH9h7D4lg[/youtube]