Bridge repair Canberra style

pandaman said :

Joker said :

niftydog said :

pandaman said :

So here’s the thing right: I studied physics…

Orrrrr, it’s an old pier and the bearing is still there, just not visible in the photo, and the bricks/wood are simply holding the canvas down.

nah… that’s to logical.

Aaaaaand, I walked under that bridge while work was starting up a few weeks back and that column wasn’t there. I reckon I’ll stick with my prediction. 😉

If that’s the case they really have done a sh*t job. Just look at where the wrap has split near the top. Pretty shoddy concrete job I would say. Also you can see the plate where the ‘bearing’ is. Looks to me like they are re-enforcing these piers rather than putting new ones in.

The Frots said :

+1 big time!!! What the hell are they thinking with this?

I think that Simon C should make a grand effort and drive over it, under it, park, etc to show us all its okay!!!

Simon’s too busy opening things. Put a ribbon on it with some scissors nearby, microphone and TV cameras and he’ll be there.

The Frots said :

kezzafezza said :

gentoopenguin said :

Mental note: do not drive over this bridge.

Or under it!

+1 big time!!! What the hell are they thinking with this?

If you were to drive under the bridge I’d hope your car was waterproof. Ginninderra Creek is a pretty damp road.

Also traffic on the bridge has been reduced to one lane. I assume on the opposite (still bolstered/supported) side. I’d be surprised if we see another GDE-style failure here.

Joker said :

niftydog said :

pandaman said :

So here’s the thing right: I studied physics…

Orrrrr, it’s an old pier and the bearing is still there, just not visible in the photo, and the bricks/wood are simply holding the canvas down.

nah… that’s to logical.

Aaaaaand, I walked under that bridge while work was starting up a few weeks back and that column wasn’t there. I reckon I’ll stick with my prediction. 😉

niftydog said :

pandaman said :

So here’s the thing right: I studied physics…

Orrrrr, it’s an old pier and the bearing is still there, just not visible in the photo, and the bricks/wood are simply holding the canvas down.

nah… that’s to logical.

pandaman said :

So here’s the thing right: I studied physics…

Orrrrr, it’s an old pier and the bearing is still there, just not visible in the photo, and the bricks/wood are simply holding the canvas down.

So here’s the thing right: I studied physics in my high school years and I have worked a bit with concrete, so I reckon I can shed some light on what’s going on in this photo. (So long as anyone’s interested in the slightly nerdy side of things anyway)

To begin: Bridges are often designed to have an interface between the deck and the supporting member (abutments and piers) to allow for reaction forces from traffic loading (and thermal expansion and all that jazz) to be taken up by something that is not concrete, which has a history of not taking well to bending forces. This interface is called a bearing. Often this takes the form of a large chunk of rubber with steel reinforcing plates in it. (I think that’s what they’re using on this bridge, you can see a couple of black blobs in the background at the abutment)

Next. That column appears to be wrapped in some sort of fabric. This suggests to me that it has only recently been poured and they’re trying to protect the concrete from losing too much moisture to the sun and wind. (Drying cracks all over a brand new column is sure to piss off the client ya see, I know that they hate it with floor slabs) :p I’d probably do things a little differently if it were my column but I’m just paranoid about these things.

Thirdly. If the concrete has only been poured recently, it will not be at full strength yet. Placing the bearing and trying to support a couple of hundred tonnes on concrete that’s a couple of days old is sure to have hilarious results that will probably also piss the client right off, but would make for a fantastic public art installation ala stanhope.

So here’s the hot tip. I reckon in a couple of weeks time, (or more, depending on how strong the concrete needs to be) that column will have the fabric taken off it, the bridge will be jacked up and a chunk of rubber and steel thrown into the gap. In the meantime though it is a pretty funny look, although it would have been better if the wood was in the middle of the pier so it actually looked like a half arsed propping effort. :p

It will ride up with wear.

The work on these bridges is to provide additional strength for “Heavy Vehicles”… The (mildly graffiti-coated) concrete walls in the background are the current (and adequate) supports. Perhaps the constant convoy of trucks moving goods to Dunlop Woolworths require this trade route. I wouldn’t be too concerned, unless it is still like that when the work is completed in late September… It does, however, make a strikingly humourous photo; great find! 🙂

Before accusing the gov and builders of doing a half arsed job, how about letting them finish it first. I mean to say this job is meant to take about 3 months and has only been going a few weeks.

As for the picture, if I am not mistaken the concrete pier never touched the deck, instead there is/was some kind of plate on top which transfered the weight. I also have no doubt that if that plate has been removed there are some other temporary supports somewhere else or the bridge is capable of being safe without it.