San Francisco- Oakland Bay Bridge

By Metarinka (****)

Date 10-28-2009 15:51

what's the story this time? still having the weld cracking issues?

By ravi theCobra (**)

Date 10-28-2009 16:24

No, they just had 40 - 60 MPH winds in the Bay area and a whole bunch of stuff came down -

By waccobird (****)

Date 10-28-2009 16:30 Edited 10-28-2009 16:34

By LISA LEFF and JOHN MARSHALL, Associated Press Writers – Wed Oct 28, 7:50 am ET
SAN FRANCISCO – The San Francisco-Oakland Bay Bridge has been closed indefinitely after a rod installed during last month's emergency repairs snapped, causing a traffic nightmare for the 26,000 motorists who cross the landmark span every day.
Engineers on Wednesday will evaluate the damage caused when the rod and metal brace fell into the 73-year-old bridge's westbound lanes during Tuesday evening's rush hour.
At least two vehicles — a car and a small truck — either were struck by or ran into the fallen rod, said California Highway Patrol Officer Peter Van Eckhardt, but no injuries were reported.
The California Department of Transportation said Tuesday that it will remain closed indefinitely.
A spokesman for the Bay Area Rapid Transit District, meanwhile, said extra trains would run during the morning commute.
The rod that fell Tuesday was erected last month during an emergency repair job. It was holding in place a saddle-like cap that had been installed over a cracked link discovered over the Labor Day weekend.
When the rod apparently snapped at about 5:30 p.m., it brought down with it a steel patch roughly 3 feet long, authorities said.
"If you look at the totality of the circumstances — you've got the 5:30 commute, you have a 5,000-pound piece of steel falling out of the sky. We are so fortunate that no one was injured or killed," CHP Sgt. Trent Cross told KTVU-TV.
Officers managed to clear the Oakland-bound traffic from the lower deck of the bridge by 8 p.m. but were still clearing cars from the few remaining open lanes of the upper deck an hour later, he said.
The bridge was closed last month over the holiday weekend while long-planned earthquake safety upgrades were being made to the bridge. When the crack was discovered, state transportation officials initially feared it would prevent them from reopening the span in time for the start of the work week.
But the unexpected work only ended up taking a few extra hours.
California Department of Transportation, or Caltrans, officials had nothing to say Tuesday about what might have caused the repair job to fail. The department issued a brief statement saying only that "structural engineers and inspectors are onsite to assess the damage and will make a determination as to how long repairs will take.
"At this time, the bridge is closed until further notice," the statement said.
Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley who has spent 20 years studying the Bay Bridge, called the initial crack a "warning sign" of potentially bigger safety issues with the bridge.
"The repair they were doing was really a Band-Aid," said Astaneh-Asl, who criticized Caltrans at the time for rushing to reopen the bridge. "The Band-Aid broke, in essence."
Astaneh-Asl said the failure of the repair job demonstrates the need for a longer-term solution. The bridge's age and design make it susceptible to collapse, especially if commercial tractor-trailers are allowed to continue using it, he said.
"I think Caltrans is putting public relations ahead of public safety," he said.

By Metarinka (****)

Date 10-28-2009 16:50

wow.

If I was the welder who did those repairs, or the Engineer who signed off on the repair job I would be a little nervous today. Probably be awhile till we know what's really going on.

By ravi theCobra (**)

Date 10-28-2009 16:59

. . . . . if ever . . . . !

By Metarinka (****)

Date 10-28-2009 17:23

good point, might be one of those hushed hushed things. That a bunch of senior engineer types will be in the corner talking about. within CalTrans I could see a lot of people trying to pass the buck or dodge the responsibility. Could be a case of bad design, oversight in calculations, or bad manufacturing... interesting to know

By mightymoe (**)

Date 10-28-2009 21:23

Let's go back to old fashioned rivots.

By DaveBoyer (*****)

Date 10-29-2009 01:14

"The repair they were doing was really a Band-Aid,"

A repair of that magnatude needs DUCT TAPE, not a band aid...

They are darned lucky no one was hurt.

By jrw159

Date 10-29-2009 01:36

"A repair of that magnatude needs DUCT TAPE, not a band aid..."

LMAO thats good. Sounds like it would have held longer with duct tape. My mother in law is famous for duct tape repairs. You give her three rolls of duct tape and she could probably stop the earth from spinning.

http://www.youtube.com/watch?v=1BSDZJSKiVI

jrw159

By G.S.Crisi (****)

Date 10-28-2009 18:37

As I've never been in San Francisco, don't get offended if I ask the following question: are you talking about the famous Golden Gate?
Giovanni S. Crisi
Sao Paulo - Brazil

By ravi theCobra (**)

Date 10-28-2009 18:43

The Golden Gate Bridge is a relatively short bridge that goes from San Francisco to Marin County and into the Wine Country -

The San Francisco - Oakland Bridge is about 2 1/2 miles long and has an exit point at Treasure Island (once a Navy base ) along

By ssbn727 (*****)

Date 10-29-2009 04:16

True Ravi but, the Golden Gate is a suspension bridge which has a longer span than any of the spans on the San Farancisco - Oakland Bay bridge which is really a series of spans and none of them are as long as the main suspension span of the Golden Gate bridge which is currently rated as the ninth longest completed suspension bridge at 1280 Meters, or 4,200 ft. long from tower to tower was opened in 1937... The San Francisco to Oakland Bay Bridge is really tow spans of 704 Meters, or 2,310 ft. long each from anchorage to Yerba Buena Island and from anchorage to San Francisco was opened in 1936 respectively... In other words, two very different types of bridges Giovanni! ;)

The current longest suspension bridge is the Akashi-Kaikyo Bridge also known as the Pearl Bridge which is measured by the length of the center span of 1,991 meters, or 6,532 feet which is equal to 1.24 miles. It is located in Japan and was completed in 1998.

There are tow bridges where preliminary work has, or is about to be started... they are the Strait of Messina Bridge and the Sunda Strait Bridge...
The Strait of Messina Bridge will have a main span of 3,300 Meters, or 11,000 ft long which is equal to 2 miles, 440 ft. long!!! Almost twice the length of the current record holder of 1.24 miles for the Akashi-Kaikyo Bridge!!! ;) ;) ;) work on the bridge was canceled by the Italian Government in 2006 for fears of substantial cost overruns and significant Mafia influence, and then in 2008, the project was revived by the current government wants to pick up the project again. Preliminary works will begin in December 2009. The main construction is expected to begin before the end of 2010 and completed in 2016.

Now the Sunda strait Bridge is just a tad shorter in it's main span... It will connect Java and Sumatra, Indonesia but with recent events, it may just be postponed a bit longer as seismic activity has increased significantly and design re-considerations will probably become a priority... This project has been approved by the Indonesian government. If completed, it will not only be the world's longest suspension bridge 26 km in total length, but will also have a main span of about 3,000 Meters, or, 9,800 ft. long and roughly fifty percent longer than the current record!!! :) :) :)

There is another bridge with the same length main span that is currently unnamed that is also being built in China... A suspension bridge is being considered to cross the 22.5 kilometer wide Qiongzhou Strait. One design consists of four bridges strung together with four main spans of 2,000 meters, two main-spans of 1,800 meters, five anchorages and 10 towers. If completed this bridge will assume six of the top seven longest spans!!! now that's a whole lot of bridge building!!! :) :) :)

Now the bridge which handles more traffic than any other is hand down, the George Washington Bridge connecting New York City with the State of New Jersey and the City of Fort Lee. This suspension bridge has the most lanes of traffic - fourteen!!! ;) ;) :)

I ought to know this from being born and raised in New York as well as presently residing in the City of Bridges; Pittsburgh, PA

Respectfully,
Henry

By ravi theCobra (**)

Date 10-29-2009 16:09

Did I see Duquensque Boulevard on that sign ?

By ssbn727 (*****)

Date 10-29-2009 16:13

Pittsburgh Proper!!!
Yes sir!!! :) :) :)

Respectfully,
Henry

By Duke

Date 10-28-2009 21:30

CalTrans is saying it was the wind... I have talked to several structural engineers who say BS. The pictures I have seen seem to show Dyiwidag bars, not 'cables' as the news reports have it. The bridge was cut over Labor day, you might remember, and the cracked eyebar was discovered at that time. (several hundred feet from the section that was cut, and new section installed) A lot of stresses that are probably misunderstood have been induced into the remaining structure as a result. I am staying off of that bridge, and I'm not so sure about the new one, either.

By Duke

Date 10-28-2009 21:33

snip...
"Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley who has spent 20 years studying the Bay Bridge, called the initial crack a "warning sign" of potentially bigger safety issues with the bridge.
"The repair they were doing was really a Band-Aid," said Astaneh-Asl, who criticized Caltrans at the time for rushing to reopen the bridge. "The Band-Aid broke, in essence."
Astaneh-Asl said the failure of the repair job demonstrates the need for a longer-term solution. The bridge's age and design make it susceptible to collapse, especially if commercial tractor-trailers are allowed to continue using it, he said.
...snip
Mr. Astaneh-Asl doesnt like the design of the new bridge, either.

By G.S.Crisi (****)

Date 10-28-2009 23:29

Duke,
the old generation bridges, such as Brooklin and Golden Gate, called "suspended" or "hanging" bridges, employed steel cables. The new generation bridges, as the San Francisco - Oakland and the bridge over the Bosphorus strait between the European and the Asian side of Istanbul, called "stayed" bridges, employ steel bars. Of course, newspapers don't know the difference between them two and keep on saying "cables".
Giovanni S. Crisi

By Duke

Date 10-29-2009 03:11 Edited 10-29-2009 03:18

actually, this portion of the bridge, the span east of Yerba Buena Island is neither suspended nor cablestayed... it is commonly referred to as "the cantilever section" and looks like a big old truss to me. The bars in question were a repair to carry tension around a cracked eyebar. if this posts correctly, you can see the cracked eyebar, inside bar of the 4 on the right. (picture 2 of 19) http://www.sfgate.com/cgi-bin/object/article?f=/c/a/2009/10/28/MNO81ABJTF.DTL&object=%2Fc%2Fpictures%2F2009%2F10%2F27%2Fmn-bridge28_023__0500771088.jpg

By JMCInc

Date 10-29-2009 16:40

Looks like all the other eyes there had strongbacks welded on the areas prone to cracking. Why didn't they just take care of them all while they were there? Anything to save a buck......

By JMCInc

Date 10-29-2009 16:53

BTW, Duke, Thanks for the link. I've been looking for some pics of what really happened. Those rods breaking demonstrates the tremendous loads levied on the connections. It never ceases to amaze me how weight can sneak up and bite you in the butt. Despite the best computer programs, education, etc. I'm surprised the bridge has't fallen down.

By ssbn727 (*****)

Date 10-29-2009 18:11

Darwin award winner for sure!!! I don't know why they couldn't replace them just as easily the first time around!!! Those clowns who approved the job ought to be stripped of their licenses - PERIOD!!!

Respectfully,
Henry

By HgTX

Date 11-02-2009 17:00

Where are you seeing strongbacks?

My understanding of the cracked eyebar situation was they were trying to figure out what to do to get the material welded, how to sample it for metallurgy, etc. You don't just walk up to historic steel with your favorite rod and start welding away.

The repair that failed was, from what I've heard, intended to be temporary, while they came up with a safe way to fix the eyebar itself (which looks to be in place still). It was not intended as a permanent repair or a cheap alternative. (That said, it clearly didn't perform even as intended, and yeah, I wouldn't want to be the person who signed off on the repair design.)

Hg

By JMCInc

Date 11-02-2009 23:31

I’m seeing some sort of repair or re-enforcement on the shoulder of each of the large eyebars, except the one that is currently failing. The modifications that I’m talking about look like they were done quite a while ago, as evidenced by the rust and discoloration at the repair area. That prompted me to make the observation that I’m not surprised some bean counter would order only the ones that may be questionable (hairline cracks that we can’t see, maybe) to be fixed. Logic would dictate that if the others are failing, then the one right next to it would eventually have a problem too. Why not shore them all up while they’re there.

By HgTX

Date 11-02-2009 23:44

Are you sure those areas aren't where they ground off the paint to perform mag particle testing or UT after the fracture was discovered in September?

Hg

By JMCInc

Date 11-02-2009 23:48

Didn't consider that. I saw a few shadow lines indicating material added and made an assumption. What are the chances we can get one of those hard hats standing around to send us a few close ups for deliberation? LOL

By ssbn727 (*****)

Date 10-29-2009 16:30

Hmmm, This is what Wikipedia says:

It is a gravity anchored suspension bridge with steel pylons and inclined hangers. The aerodynamic deck is hanging on zigzag steel cables. It is 1,510 m (4,954 ft) long with a deck width of 39 m (128 ft). The distance between the towers (main span) is 1,074 m (3,524 ft) and their height over road level is 105 m (344 ft). The clearance of the bridge from sea level is 64 m (210 ft). The Bosphorus Bridge had the 4th longest suspension bridge span in the world when it was completed in 1973, and the longest outside the United States. At present, it is the 16th longest suspension bridge span in the world.

http://en.wikipedia.org/wiki/Bosporus_Bridge

Respectfully,
Henry

By Cumminsguy71 (*****)

Date 10-30-2009 22:30

That last picture from the link Duke posted looks like it would really suck, all that traffic!! Yikes! Glad I don't have to deal with that mess everyday.

By ronnie taylor (**)

Date 11-02-2009 19:57

Kinda reminds me of crashville, sorry I mean nashville every afternoon.