Post by: dolphin on August 12, 2007, 07:33:44 AM
I used to walk across the The Fort Steuben bridge when I was in my teens, before I started driving. It has an open grid deck. Even back then while walking it, you could feel it move when vehicles passed. I just drove across it about a month ago. It does look terribly old and rusty. Scary now!!!
Post by: kimmer on August 12, 2007, 01:17:01 PM
You walked across an open grid deck bridge? Not me.
Nevah! I don't even like driving over them - or over any bridge.I have walked across small wooden bridges and almost lost my cookies by the time I get across.
I didn't know that Homer Laughlin China Co owned a bridge.
I have some of their Fiestaware in my cabinet. Great stuff.
Post by: Gregg on August 12, 2007, 04:30:22 PM
I walk across draw bridges(? - bridges that open for boats) in downtown Milwaukee. Some are open grid decks, some have steel plates on the pedestrian walk, and they move quite a bit. It sure gives you pause when a big truck is coming, and you're in the middle! The newest bridge is more solid, but having walked over it only a couple of times, I'm not sure what the deck is make of. I took more than two years to rebuild it. Now another one is closed for replacement. I hope this means they are on top of the situation around here.
Post by: dolphin on August 13, 2007, 07:10:09 AM
QUOTE(kimmer @ Aug 12 2007, 02:17 PM) <{POST_SNAPBACK}>
You walked across an open grid deck bridge? Not me.
Nevah! I don't even like driving over them - or over any bridge.I have walked across small wooden bridges and almost lost my cookies by the time I get across.
I didn't know that Homer Laughlin China Co owned a bridge.
I have some of their Fiestaware in my cabinet. Great stuff.The key is to NOT look down Kimmer!!!
Post by: Xairbusdriver on August 13, 2007, 06:31:33 PM
In truth, most structures built in the last 75 years had a general life built into them. They can be used much longer than that with proper maintenance. All commercial aircraft have pieces removed over a matter of years until the whole thing is actually 90% newer than when it first left the factory.
The problem, IMHO, is that most agencies responsible for the maintenance can not do an adequate job of getting budgets approved from the politicians who have to also approve/create the taxes. They tend to give in to voters who want the same or more services without paying for them. Immediate needs always trump future possible needs. This applies to more than "infrastructure", of course. Any teachers out there getting more supplies for your classes?
Who said anything about a pay raise?! 
Ah, but we Shelby Countians have a brand spanking new basketball area! No, we didn't get to vote on it, no, we hadn't paid off the last one yet, no the costs didn't come in under budget, even though part of the building was never built and which the feds now want their contributions returned (with interest). STOP ME! 
Post by: sandbox on August 13, 2007, 09:03:35 PM
Someone did something wrong here. Either the authority that authorized the work permit and plan, or the construction crew who did not follow the plan. Granted the bridge was in need of repair but I suspect under normal circumstances it would have never experienced total failure.
The investigation will take a long time and each responsible party are lining up their lawyers now. If you want to know what happened before they come out with the final report watch how they change their resurfacing procedures on other bridges in the future. I bet they do not shift traffic to one side of the bridge while resurfacing the other.
Post by: Xairbusdriver on August 13, 2007, 09:31:08 PM
I think they have already found certain welding techniques that are no longer allowed. It goes back to what I said about flexibility. Most structures cannot nor would you want them to be completely rigid. First, they cost would skyrocket from over building. Second, they would require even more maintenance and inspections. Next time you fly a wide-body, take a look at the wingtips; if there is any turbulence, you will see it flex up and down. Were it not to do that, the cabin would have to be made smaller because more of the aircraft weight would be in the structure. And the ride would be considerably rougher.
The ultimate cause(s) will probably be minor but linked to others until the final straw breaks. And Sandbox is correct, it will take time. And the movement you felt has been happening since before that bridge was even opened. You are simply more aware of it now, for a while, anyway. I don't think we can really continue living as most of us want to and completely avoid bridges, airliners, domed stadia, etc.
Let's just hope that the agencies that are in charge of maintenance can keep the money handlers attention to get better inspections, quicker repairs and better designs.
Post by: sandbox on August 13, 2007, 11:37:58 PM
QUOTE
I may be just plain simple
ya think? QUOTE
but how do you allow resurfacing of a lane and travel on it at the same time?
is that a real question?QUOTE
If shifting the traffic is part of the problem you'd better hope there is never a wreck that blocks a lane and traffic has to detour around it.
equating accident recovery and proportional course deviation too a two lane at a swipe resurfacing project is a leap that few would make.Lengthy Time of the project, focused weight of aggregate and machinery, the ground shaking vibration generated from the resurfacing procedure that is not found in normal traffic flow, added to the shifted weight of rush hour traffic to one side of the bridge is something you may want to add to your simple equation.
Post by: Gregg on August 14, 2007, 07:28:52 AM
QUOTE(Xairbusdriver @ Aug 13 2007, 06:31 PM) <{POST_SNAPBACK}>
Most large construction is built to be slightly flexible. From your car all the way to a skyscraper. The trick is to engineer the flexibility into points that can handle the flexing without breaking.
Sometimes, there's too much deflection, even if the structure is safe. A shopping mall where I went to college is a good example. A department store had its china and crystal display at the top of the escaltor. There was so much vibration from the "stairs" and people walking by, that the dishes rattled! You could feel the movement. Another building on campus, where I worked, shook from the mechanical equipment in the basement. Until I knew what was causing the feeling, I thought I was having an anxiety attack!
QUOTE
I may be just plain simple but how do you allow resurfacing of a lane and travel on it at the same time?
Maybe the trucks they were using were made by Dodge?
QUOTE
Lengthy Time of the project, focused weight of aggregate and machinery, the ground shaking vibration generated from the resurfacing procedure that is not found in normal traffic flow, added to the shifted weight of rush hour traffic to one side of the bridge is something you may want to add to your simple equation.
There you go, what he said; plus that part about a bad plan, or not following a sound plan.
Post by: sandbox on August 14, 2007, 12:37:46 PM
I have seen a road crew working on a repavement project fall into a sinkhole that the vibrator created by not adjusting it’s frequency which resulted in shaking apart a limestone cavern 30 feet below. This is a detailed procedure on bridges and tunnels or near previous built pipelines, sewers, or dams. I suspect as others in the construction trades do that the resurfacing project had much to do with the failure of that bridge. Not that our bridges couldn't use more attention, of course they could, and should we expect to be concerned about bridges that we cross, of course, all I'm saying is that one should be more concerned about bridges they cross that are under construction.
Post by: Gregg on August 14, 2007, 01:16:05 PM
QUOTE(Gregg @ Aug 12 2007, 04:30 PM) <{POST_SNAPBACK}>
That story is kind of scary.
I walk across draw bridges(? - bridges that open for boats) in downtown Milwaukee. Some are open grid decks, some have steel plates on the pedestrian walk, and they move quite a bit. It sure gives you pause when a big truck is coming, and you're in the middle! The newest bridge is more solid, but having walked over it only a couple of times, I'm not sure what the deck is make of. I took more than two years to rebuild it. Now another one is closed for replacement. I hope this means they are on top of the situation around here.
I walk across draw bridges(? - bridges that open for boats) in downtown Milwaukee. Some are open grid decks, some have steel plates on the pedestrian walk, and they move quite a bit. It sure gives you pause when a big truck is coming, and you're in the middle! The newest bridge is more solid, but having walked over it only a couple of times, I'm not sure what the deck is make of. I took more than two years to rebuild it. Now another one is closed for replacement. I hope this means they are on top of the situation around here.
Went over there today. It's a boardwalk! How "permanent" is that???
Post by: sandbox on August 14, 2007, 03:36:52 PM
The earth knows no denigration, it sees it's restoration in the piles of decay.
Post by: Gregg on August 15, 2007, 07:26:42 AM
No such thing as permanent though. If a structure is safe for 500 years, but begins to break down, you either repair it or demolish it and start over.
There are some old wooden bridges still in use. Of course, those have roofs with asphalt shingles to protect the deck from the rain and sun. This new bridge downtown has an exposed boardwalk. They'll be replacing that with great regularity!