The new Bay Bridge

[Pete from Boston]

Designed to last until the 22nd century....I would count on it.

22nd century? What evidence is it based on? Geez we need to wait for the next quake to find out now that leaks are mentioned.

This reminds me of the Lazlo Toth objection to the Department of Energy paying Bechtel in full for nuclear waste storage facilities designed to last 10,000 years.  Pay half up front, Toth argued, and half after 10,000 years if the results are satisfactory.

Perhaps the final payment on the bridge should remain in escrow for 86 years.

[kkt]

Maybe that would be a good payment arrangement for major engineering works in general.  If the firm is at the edge of solvency, they can merge with some other firm who takes over the future payment but also the obligation to fix it in the meantime if necessary.

[pctech]

Oops, just caught my typo. I meant don't count on it lasting until the 22nd century.....

[kkt]

Oops, just caught my typo. I meant don't count on it lasting until the 22nd century.....

Why not?  That's only 87 years away.  Should be nothing for a well-engineered bridge.

[vdeane]

Given these cracks, this bridge might not be so well-engineered.

[ZLoth]

And the hits keep on coming...

From SF Gate:

Caltrans kept Bay Bridge leaks from local officials

Local transportation officials are demanding that Caltrans reveal any problems with the new Bay Bridge eastern span after the state agency failed to tell them for nearly two months that potentially corrosive rainwater was leaking into the steel superstructure.

"An oversight committee can't oversee if it is not provided with information from the project staff," said Steve Heminger, executive director of the Metropolitan Transportation Commission. "I have made that clear in no uncertain terms."

In his update on the bridge project last week, which was not publicized, Heminger revealed that Caltrans didn't tell commission staffers of the leak problem - which carries the risk of corrosion over the long term - until late January, though the state knew about it in early December.

FULL ARTICLE HERE

[kkt]

Oops, just caught my typo. I meant don't count on it lasting until the 22nd century.....

Why not?  That's only 87 years away.  Should be nothing for a well-engineered bridge.

I happened to read today that old London Bridge lasted over 600 years.  There are probably older examples, but it had heavy use its whole life.

[english si]

I happened to read today that old London Bridge lasted over 600 years.  There are probably older examples, but it had heavy use its whole life.

The 7th bridge lasted from 1209 to 1831. And it was the Georgian demolition of the houses and widening of the bridge that caused the structural reasons for the bridge, now in Arizona, being built.

Of course, the 12ft roadway stopped heavy vehicles, such as we see now, from using it. 7-storey buildings, however, do add a lot of load onto the structure. Add in that London is sinking into the soft clay, and it is especially a bridge problem (the 1831 bridge was sinking about an inch every 8 years) and for a bridge to last that long is epic.

Plus, it was the only bridge downstream of Kingston until Waterloo Bridge was opened, prompting the 1760s widening. And the nursery rhyme tells of its falling down. Both point to the engineering difficulty in bridging the river (OK there's political reasons why no other bridges, as well as South London not developing until the industrial revolution). 1209 had some chuffing good engineers!

[kkt]

Of course, the 12ft roadway stopped heavy vehicles, such as we see now, from using it. 7-storey buildings, however, do add a lot of load onto the structure.

Pedestrians packed shoulder-to-shoulder across a bridge can put more weight on the span that a typical load of cars and trucks.  The Golden Gate Bridge is slightly arched in the middle.  When the bridge was closed to car traffic and jammed wall-to-wall with pedestrians for the 50th anniversary celebration, the weight was so much the center arch flattened out.  That never happened when it was open to vehicle traffic, even bumper to bumper commute traffic.

Yep, those 13th century stonemasons knew what they were doing.

[agentsteel53]

I happened to read today that old London Bridge lasted over 600 years.  There are probably older examples, but it had heavy use its whole life.

plenty of bridges in Europe that are about that old, if not older. 

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

I'll bet we can find a Roman bridge that is open to vehicular traffic today.

[Jardine]

IIRC, the Alcantara bridge pictured on that ref'd Wiki page is open to vehicular traffic.

[ZLoth]

From SF Gate:

Caltrans was warned Bay Bridge welds could crack

The firm that designed the new Bay Bridge eastern span warned Caltrans as the bridge neared completion that some of its welds could crack prematurely under the constant pounding of cars and trucks, The Chronicle has learned.

The potential for cracking was created after the span was designed, said engineers with the firm T.Y. Lin International. It happened when Caltrans suspended its rules and allowed the bridge builder to weld together Chinese-manufactured sections of steel road deck that didn't fit together correctly.

Any cracks in the welded connections would be minor, the engineers concluded, and would not pose the threat of a catastrophic failure. However, such cracking could shorten the time before toll-payer dollars would be needed to make repairs to the $6.4 billion bridge.

FULL ARTICLE HERE

[ZLoth]

From Sacramento Bee:

New Bay Bridge shows signs of rust in critical areas

The bridge suspension span and iconic tower rely on an unusual design: A single cable, comprising 137 steel strands, loops over the tower and under the bridge to hold it up. That cable is secured on the eastern edge of the span, inside chambers designed to keep out water and marine air to prevent corrosion.

But a Sacramento Bee investigation found that inside one of the chambers, where the suspension cable is attached, the cable strands and rods show rust. Lab tests confirm the rust, alarming independent engineering experts who warn of severe long-term implications. They urge the California Department of Transportation to move quickly to fix the problem.

FULL ARTICLE HERE

[kkt]

How not to build a bridge.

[ZLoth]

From SF Gate:

Caltrans' simple, cut-rate fix for Bay Bridge problem

Even as Caltrans spends $10 million to study whether more than 2,000 rods and bolts on the new eastern span of the Bay Bridge are vulnerable to cracking, the agency has quietly installed a relatively cheap and simple fix for dozens of the galvanized-steel parts, The Chronicle has learned.

FULL ARTICLE HERE

[ZLoth]

From SF Gate:

Optimistic report on new Bay Bridge's maintenance

None of the issues that have arisen in the past year-plus on the new Bay Bridge eastern span should result in extra maintenance costs over the expected 150-year life of the bridge, the project manager for the new span said Tuesday.

A Bay Area transportation official ordered up a list of potential maintenance headaches after The Chronicle reported in February that the huge, hollow steel structures that support the road decks on the tower portion of the bridge leak when it rains, raising the threat of rust and a shortened life for the span.

FULL ARTICLE HERE

[ZLoth]

When will the fun ever stop?

From SF Gate:

New Bay Bridge defect could be trouble in earthquake

Steel rods that anchor the Bay Bridge eastern span's massive main cable have shifted since they were installed and are now perilously close to sharp-edged plates inside the belly of the new span, a problem Caltrans acknowledges could take months and millions of dollars to fix, The Chronicle has learned.

Caltrans engineers say more than 200 high-strength rods could be jerked in a major earthquake into those sharp edges, risking damage to the main cable and possibly threatening the bridge's stability.

Caltrans has known about the problem for several months, but Bay Area transportation officials who will soon be responsible for maintaining the bridge say they learned of it only recently. They want it dealt with before the state officially turns over the bridge to local authorities, which is supposed to happen in August.

FULL ARTICLE HERE

[kkt]

When will the fun ever stop?

From SF Gate:

They want it dealt with before the state officially turns over the bridge to local authorities, which is supposed to happen in August.

I don't understand turning over the bridge to local authorities.  Caltrans isn't going to be maintaining the bridge throughout its life?  Who is?

[Bickendan]

If the bridge is getting turned over to local authorities, does that mean that I-80's getting truncated back to the MacArthur Maze?

[oscar]

If the bridge is getting turned over to local authorities, does that mean that I-80's getting truncated back to the MacArthur Maze?

My quick review of cahighways.org, and the state highway code, suggests there are no plans to "relinquish" (remove from the state highway system) the Bay Bridge part of route 80.  That's unlike what's happened to several other routes, like CA 1, that have been sliced and diced through relinquishments to county or municipal governments.

As discussed over in another recent thread, at least part of I-215 in Nevada is county-maintained, so the lack of state maintenance seems not inconsistent with Interstate status.

[bing101]

When will the fun ever stop?

From SF Gate:

They want it dealt with before the state officially turns over the bridge to local authorities, which is supposed to happen in August.

I don't understand turning over the bridge to local authorities.  Caltrans isn't going to be maintaining the bridge throughout its life?  Who is?

What I thought Caltrans is the owner of the Bridge? that makes no sense why would caltrans throw away money that they get from the Fastrak tolls?

[JustDrive]

But it could be like the Golden Gate Bridge, where it's not a part of either US 101 or SR 1, right?

[myosh_tino]

What I thought Caltrans is the owner of the Bridge? that makes no sense why would caltrans throw away money that they get from the Fastrak tolls?

Except Caltrans doesn't see any of the toll revenue per se.

The Bay Area Toll Authority (BATA), created by the state legislature in the late 90's, handles ALL toll revenue from the 7 state-owned bridges (San Mateo, Dumbarton, San Rafael, Benicia, Carquinez, Antioch and the Bay Bridge) and uses those funds for day-to-day operations and maintenance of these bridges along with funding certain capital improvement projects.

[andy3175]

But it could be like the Golden Gate Bridge, where it's not a part of either US 101 or SR 1, right?

The Golden Gate Bridge is not part of the BATA that myosh_tino mentioned; instead, it is part of the Golden Gate Bridge, Highway and Transportation District (see http://www.goldengatebridge.org/). BATA (http://bata.mtc.ca.gov/about.htm) was created in 1997; the Golden Gate District was formed in 1928. Since BATA is a comparably recent state legislative creation, my suspicion is that BATA-controlled bridges are considered part of the state highway system. I think that since the GGBHTD is a special purpose district and is much older with a different background, the Golden Gate Bridge is not a part of the state highway system.

For purposes of route continuity, US 101 and SR 1 are both signed on the approaches to the bridge; however, California's Streets and Highways Code (http://www.leginfo.ca.gov/cgi-bin/displaycode?section=shc&group=00001-01000&file=300-635) notes route disruptions for both routes at the bridge approaches. Having said that, in the case of US 101, there is no route continuity issue from AASHTO's perspective. In the latest US highways log (http://route.transportation.org/Pages/U.S.RouteNumberDatabase(Dec2009).aspx), there is no disruption listed; therefore, AASHTO considers US 101 to be part of the Golden Gate Bridge.

Similar instances where FHWA and/or AASHTO and California's Streets and Highways Code vary include Interstate 210 along the north-south SR 57/Orange Freeway segment (FHWA still considers this short segment between SR 210 and I-10 to be I-210; California's code considers it to be SR 57). Interstate 305 (listed in the FHWA Route Log and Finder List but not in the California Streets and Highways Code). It is debatable whether I-80 west of the Bay Bridge has a similar discrepancy, as some sources question whether I-80 west of the Bay Bridge was ever officially added into the Interstate Highway System.

[bing101]

Is this like Port Authority in New Jersey and New York State where they manage the bridges such as the I-95 George Washington Bridge but the state of New York and New Jersey DOt's manage other freeways in the state that does not land on state borders.


But the strange thing is that I see CalTrans have offices and trucks on the Carquinez Toll Plaza and Bay Bridge Toll plaza I never knew it was really managed by BATA.