Another bridge knocked down.

[crazyal]

Up north bridges can't be bolted down on both ends. With the changes in temps the bridge needs to move to expand and contract or it will not be called a bridge for very long. When you drive over a bridge you can see the expansion joint. Sometimes they are just a gap while other times they look like finger joints use to glue wood together.

I would say that driver is very lucky a train wasn't going through.

 

[kebo]

It also looks like the towing truck was undamaged.

Except for that HUGE brown spot in the driver seat!!! :laughing:

 

[LD1]

Up north bridges can't be bolted down on both ends. With the changes in temps the bridge needs to move to expand and contract or it will not be called a bridge for very long. When you drive over a bridge you can see the expansion joint. Sometimes they are just a gap while other times they look like finger joints use to glue wood together.

That makes perfect sense:thumbsup:

I would say that driver is very lucky a train wasn't going through.

I would say you are absolutly right

 

[Whatswrong]

There may be some corelation between not being able to read the sign on the bridge and the ability to figure out how to measure from the top of the boom to the ground and realize "one of these things doesn't go with the other".Even with an oversize permit there is some law that says 2 matters can't occupy the same space at thesame time .

 

[wrooster]

It looks like someone forgot to bolt down the bridge in the first place :laughing:

How did all those Civil Engineering courses work out for ya?

You can't "bolt down a bridge" in a conventional sense -- it becomes statically indeterminate and you'll have more problems than if you just sit the road surface atop the supporting infrastructure. This allows for expansion/contraction, and better distribution of applied load.

Wrooster

 

[EddieWalker]

How did all those Civil Engineering courses work out for ya?

You can't "bolt down a bridge" in a conventional sense -- it becomes statically indeterminate and you'll have more problems than if you just sit the road surface atop the supporting infrastructure. This allows for expansion/contraction, and better distribution of applied load.

Wrooster

Does this work for a smaller wood bridge? Somthing that's 12 feet long and 8 feet wide? Or is that too small to matter?

Eddie

 

[grsthegreat]

How did all those Civil Engineering courses work out for ya?

You can't "bolt down a bridge" in a conventional sense -- it becomes statically indeterminate and you'll have more problems than if you just sit the road surface atop the supporting infrastructure. This allows for expansion/contraction, and better distribution of applied load.

Wrooster

So what happens in an earthquake where there is uplifting? do the bridges just fall apart?

 

[EddieWalker]

So what happens in an earthquake where there is uplifting? do the bridges just fall apart?

I've never thought about this before, but now I'm thinking that when I build my bridge, that if I rest it on concrete footings, it can move when the ground moves and not pull itself apart. I think this is what happens during earthquakes and other times that the soil moves. Frost heave and thawing.

Where I live, clay moves quite a bit when it gets really wet, then freezes. Most of the damage to houses happens when this happens, but most people don't notice it until spring, when the ground settles and sinks back down.

With water in my lake, I'm wondering if this freezing movement of the soil will affect my bridge over my spillway if I bolt it to the concrete footings?

Eddie

 

[bcp]

Bolt it on only one side, but not too tight.

Bruce

 

[not2old]

Someone's assuming the driver was at error, but we don't know that for sure. A number of years ago, I checked the sign posting the clearance on a McDonald's underground parking and drove in. Within seconds there was a whole lot of noise when the ladder on my truck's roof ripped through about sixty feet of aluminum soffit material before I realized what was happening and stopped. This was witnessed by a cop. "Just the person I need", I told him. He noted the clearance was posted as 7' 6" when it was actually measured at 6' 7". McDonald's gave me a wad of vouchers in consideration of the paint scratches on the roof of my beater truck.