Posted on 06/22/2014 12:55:50 PM PDT by Second Amendment First
The welding code and construction contract for the suspension-span roadway of the new San Francisco-Oakland Bay Bridge each contain a universal rule: “No cracks.”
That rule applies to any new steel bridge and is particularly important for a “fracture-critical” bridge such as the new span, which opened last fall. Fracture-critical bridges can break, because some of their parts lack redundancy or backup. If a weld crack grows larger, causing such a part to fail, all or part of the roadway could collapse.
In 2008, the no-cracks rule put the California Department of Transportation in a worrisome bind. The Chinese firm hired to build the roadway routinely produced cracked welds that proved difficult to fix. Facing rising costs and increasing delays on a $6.5 billion bridge that was already years behind schedule and billions over budget, Caltrans sought advice about its options from a highly regarded expert in how metal fractures. He said some cracks can remain without compromising safety.
Caltrans then changed its contract and decided to put aside the welding code. Its fracture-critical bridge could now have cracks.
Weld cracks are the latest in the litany of errors and construction problems regarding the new span that have steadily emerged in recent years. Suspect foundation concrete, rusted tendons in the skyway that connects the suspension span to Oakland, broken anchor rods, and corrosion on the main cable are among the issues uncovered by The Sacramento Bee and others.
(Excerpt) Read more at sacbee.com ...
Costs always dictate engineering. All the engineering I ever did had cost limitations.
They probably asked the “highly regarded expert” -(sounds like “top men” from Raiders of the Lost Ark) whether or not the cracked welds would at least hold until they are retired and gone, and he replied, “sure”, so they let it go as is.
When there is an eventual disaster, it will be blamed on evil tea party zealots who will be said to have strangled the government for funding.
Lack of redundancy caused the Minneapolis I35W bridge collapse. We were told then that modern bridges were designed with plenty of redundancy.
I’d be interested to understand why the Chinese had such trouble making decent welds.
Remember the “rule of relevance”. It’s only relevant if it could affect or affects you and your family. Cracks in the welds of a bridge in Queer City are not relevant to me and my family here in Texas. Now if you live in Queer City or the surrounding area it might concern you or even render you zombie-like with fear .... but hey, that’s life in the fast lane for you.
Made in China
Are small cracks now allowed for pipelines in California?
A few hairline cracks that should be OK?
How about some wagon tracks on the x-rays? They never hurt anybody!
None of them use the bridge so what do they care!
That bridge is a cheap, imitation of an American product. ..
Stop calling him Shirley. ...
It is so. But you can't just blame the Chinese. CalTrans did a lot of stupid things. For instance, the architect specified placing caulk in channels underneath where side barrier rails would be placed and bolted down. CalTrans decided to bolt down the side barrier rails, and then lay caulk at the sides where the barrier meets the surface. So which method is a better moisture-resistant way to go? Sure enough, the caulk lifted and rainwater got under the barriers into the steel infrastructure inside the concrete. Now the steel is corroding inside the concrete, with no way to repair it bar tearing down the bridge and starting over. Imagine all those substandard welds exposed to trapped water inside the infrastructure. This is due to American substandard work by CalTrans.
To paraphrase Animal Mother, “Better California than Texas”.
And fortunately, I will never be on that bridge.
Kaliforncatia.... you get the goobermint [corruption] you deserve.
"In fiscal year 2011-12, approximately 123.67 million vehicles crossed the seven state-owned toll bridges in the Bay Area, generating approximately $642 million in total toll revenues — including $139 million in base toll revenues, $116 million in Regional Measure 2 revenues and $387 million in seismic retrofit surcharge revenues."
$669,954,595 collected in fiscal 2012-2013
Taken directly from the Bay Area Toll Authority website
California might learn a lesson here about quotas. The lesson being that while it may be ok to hire unqualified people based on their skin color or native language, you sure as heck better have ADULTS supervising their work. And, in most cases (not all, of course), those adults are WHITE and politicians there better learn to hold their noses and do this before they start seeing their bridges collapse.
This and the California High Speed Rail are art projects. They serve an aesthetic function. The useful infrastructure function could be accomplished by a much cheaper project, or by doing nothing at all.
I drove across that bridge last time I was in the Bay Area, but I think I’ll stick to the other bridges (San Mateo/Dumbarton) or just take HW 237 from now on.
Yeah, I bet they did. Using 20# copy paper, that's a stack 33 ft. high. Journalists don't have a reputation for working all that hard (unless they're trying to hang a Republican).
I have to remind my elderly mother not to listen to medical advice given by journalists. Those here unschooled in strength of materials should also heed.
Even stupid people should be capable of understanding the sensational (or truly ignorant) intent of citing an inspection report about an unqualified tack welder. Hint: they don't tell you what the disposition was. Prediction: the corrective action was to remove and replace the weld. Standard. Done every day. No need to change your commute route. In fact, that shows the system worked.
Lesson: if you ever hear of a major project that had zero negative inspection results, that's the one to avoid.
Sounds like this academic engineer lost the argument and ran to the media. Fact is, nobody knows exactly how a bridge will react in an earthquake. His is just another theory - but it sounds all scary to the unwashed masses (and, of course, the media). If perfect knowledge is the standard, we must close all existing bridges and never build another.
I lived in the Bay Area back in October of ‘89, and I saw what happened to the bridge back then.
The Chinese firm hired to build the roadway routinely produced cracked welds that proved difficult to fix.
That should have only happened once, not routinely. Someone was being bribed.
A GM product???
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