Many US bridges old, risky and rundown

[ZLoth]

From AP via SF Gate:

Many US bridges old, risky and rundown

Motorists coming off the Frederick Douglass Memorial Bridge into Washington are treated to a postcard-perfect view of the U.S. Capitol. The bridge itself, however, is about as ugly as it gets: The steel underpinnings have thinned since the structure was built in 1950, and the span is pocked with rust and crumbling concrete.

District of Columbia officials were so worried about a catastrophic failure that they shored up the horizontal beams to prevent the bridge from falling into the Anacostia River.

FULL ARTICLE HERE

[NE2]

Many US dogs manbiters

Also, nice job deannexing Anacostia from Washington.

[Alps]

Many US dogs manbiters

Every news article about bridge repairs has to go through the same rigmarole. As an engineer, it irks me, because I know that it's all media pap to create hysteria and - get this - generate readership to support advertisers to support the paper in an endless cycle.

[Big John]

The article is erroneously implying that all "fracture critical" bridges  are in imminate danger of collapse.  They need more frequent in-depth inspections of the critical components, but not in danger of collapse if designed and maintained correctly.

[707]

There are a lot of old bridges in Washington state. Many on I-5 predate the interstate itself, some of which even predate its predecessor US 99 (i.e. the northbound Interstate bridge on I-5 over the Columbia River, built in 1917 for the Pacific Highway Auto Trail). And don't forget the Skagit River Bridge in Mount Vernon (a 1955 US 99 bridge), which recently collapsed, generating nationwide attention. Lastly, before I moved to Arizona from Washington, I noticed local new channels making a big deal over the Puyallup River Bridge in Fife, also built for US 99 back in the day. Their pictures and videos showed very bad corrosion occurring along one of the metal bars above the roadway, making look like some of those rivets were holding nothing in place. I'm not saying the media is not making a bigger deal than necessary, but I'm also stating that there may be some truth to this worry.

[Henry]

I clicked on the link, and got a Page Not Found error.

I agree with that assessment, especially after witnessing the I-35W (Minneapolis) and Skagit River Bridges collapse. I'm not surprised that most of the bridges have outlived their intended lifespan (40 years for most), and I feel that something needs to be done ASAP before another potentially deadly collapse occurs.

[leroy217]

Every news article about bridge repairs has to go through the same rigmarole. As an engineer, it irks me, because I know that it's all media pap to create hysteria and - get this - generate readership to support advertisers to support the paper in an endless cycle.

You sir are correct.  You should hear what the media was saying about the I-43 bridge near Green Bay, WI a couple of months ago.  They made it seem like the entire bridge fell down.

[ZLoth]

I clicked on the link, and got a Page Not Found error.

I've updated the link. It should now point to the site bigstory.ap.org 

[Jardine]

The Minneapolis I-35/Mississippi crossing  was the big stunner for me.  The live load (including reconstruction materials) was far short of what I believe to be the load the bridge was (should have been?) designed for.

My understanding of the design requirements was the bridge should have had a margin of additional strength beyond bumper to bumper loaded trucks during gale force winds and record setting ice build up on all exposed structural elements and road surface.

You've all seen the pictures after the collapse, how far short of the above design load did the bridge fail at ??

[SteveG1988]

The Minneapolis I-35/Mississippi crossing  was the big stunner for me.  The live load (including reconstruction materials) was far short of what I believe to be the load the bridge was (should have been?) designed for.

My understanding of the design requirements was the bridge should have had a margin of additional strength beyond bumper to bumper loaded trucks during gale force winds and record setting ice build up on all exposed structural elements and road surface.

You've all seen the pictures after the collapse, how far short of the above design load did the bridge fail at ??

The bridge was non redundant, one failure can ruin any bridge like that, for example the silver bridge

[Jardine]

Which, to me, makes the meager gusset plates all the more inexplicable.

Lower chord of the truss is in tension, and the upper is in compression (simplifying a bit), and the magnitude of the forces is (should be?) first year engineering college first semester exam type question.

Another first year college topic is (should be?) Theodore Cooper.

(OMG he's invoked Cooper!)

[SteveG1988]

Which, to me, makes the meager gusset plates all the more inexplicable.

Lower chord of the truss is in tension, and the upper is in compression (simplifying a bit), and the magnitude of the forces is (should be?) first year engineering college first semester exam type question.

Another first year college topic is (should be?) Theodore Cooper.

(OMG he's invoked Cooper!)

It got a sufficiency rating of 50 before the collapse.

Whereas the 1931 burlington bristol bridge over the delaware river gets a 46.1

http://uglybridges.com/1459295

the I35W bridge was known to have problems, as do all bridges. But they were in the process of fixing it

[BrianP]

Which, to me, makes the meager gusset plates all the more inexplicable.

Lower chord of the truss is in tension, and the upper is in compression (simplifying a bit), and the magnitude of the forces is (should be?) first year engineering college first semester exam type question.

Another first year college topic is (should be?) Theodore Cooper.

(OMG he's invoked Cooper!)

It got a sufficiency rating of 50 before the collapse.

Whereas the 1931 burlington bristol bridge over the delaware river gets a 46.1

http://uglybridges.com/1459295

the I35W bridge was known to have problems, as do all bridges. But they were in the process of fixing it

Well that 46 is still better than the 12.9 that it got in 1992. 

[SteveG1988]

Which, to me, makes the meager gusset plates all the more inexplicable.

Lower chord of the truss is in tension, and the upper is in compression (simplifying a bit), and the magnitude of the forces is (should be?) first year engineering college first semester exam type question.

Another first year college topic is (should be?) Theodore Cooper.

(OMG he's invoked Cooper!)

It got a sufficiency rating of 50 before the collapse.

Whereas the 1931 burlington bristol bridge over the delaware river gets a 46.1

http://uglybridges.com/1459295

the I35W bridge was known to have problems, as do all bridges. But they were in the process of fixing it

Well that 46 is still better than the 12.9 that it got in 1992. 

They went through a major improvement program in the mid 90s, by 1990 they were expecting to replace the span, but when that got voted down they instead started to invest in their spans.

http://uglybridges.com/1369007

http://uglybridges.com/1369009

Here is a bridge that has a 4/100 rating

http://uglybridges.com/1364387 Not maintained by the county bridge comission, i've been over it and it does feel rickety

[707]

Here is a bridge that has a 4/100 rating

http://uglybridges.com/1364387 Not maintained by the county bridge comission, i've been over it and it does feel rickety

Seriously? A bridge that bad is legal?

[oscar]

Here is a bridge that has a 4/100 rating

http://uglybridges.com/1364387 Not maintained by the county bridge comission, i've been over it and it does feel rickety

Seriously? A bridge that bad is legal?

The Paihi Bridge, on the county-maintained part of Maui's Hana Highway, had a rating of just 2/100 but remained open since there were no alternate routes between Hana and Kipahulu except a multi-hour detour around the other side of the Haleakala volcano.  A 2006 earthquake on another island caused structural damage forcing its immediate closure and replacement.  The replacement is open and is undoubtedly structurally sound, though due to historic preservation restrictions it was re-built just as narrow (about 13 feet wide, just enough for one travel lane for both directions of traffic) as the old bridge. 

EDIT:  I checked the database at uglybridges.com, which does not have an updated rating for the Paihi Bridge.  It says there are several other bridges on that stretch of the Hana Highway with ratings of 2.0 or 3.0. 

[SteveG1988]

Here is a bridge that has a 4/100 rating

http://uglybridges.com/1364387 Not maintained by the county bridge comission, i've been over it and it does feel rickety

Seriously? A bridge that bad is legal?

It also has a hand cranked mechanism to open, but due to the creek being only navigatable for about half a mile to a mile, it is rarely opened.

[NE2]

That 4.0 rating is probably from before this work: http://www.southjerseylocalnews.com/articles/2010/05/07/medford_central_record/news/doc4bdf1818c79df549239415.txt