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The Science of Bridge Collapse Prevention 276

Posted by Zonk
from the so-far-we-have-not-found-the-science dept.
toddatcw writes "In the wake of the Minneapolis Interstate 35W bridge collapse this week, Computerworld investigates ongoing research which could someday help to prevent future disasters. Acoustic emissions detection systems, which listen for the sounds of metal snapping on structures, are already sold and fitted. Likewise, a new generation of detector systems that monitor for tilting of bridge columns and piers are being designed, prototyped, and researched. 'Sound waves move more efficiently through solid objects than through air, making any sounds easier to listen out for, Tamutus said. "It's not amazing. It's simple. Doctors use stethoscopes all the time. If you put your ear on a train track, you can hear a train approaching from far away... The Sensor Highway II systems, which are portable and can be moved from bridge to bridge as needed, usually cost between $20,000 to several hundred thousand dollars each. Typically, evaluations take between one day and a week.'"
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The Science of Bridge Collapse Prevention

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  • Barriers/Lights (Score:2, Insightful)

    by Archades54 (925582)
    Would this system also have a feature to alert the local road authority, or in a worst case scenario close the bridge?
    • Re:Barriers/Lights (Score:4, Informative)

      by choongiri (840652) on Friday August 03, 2007 @08:13PM (#20109579) Homepage Journal

      Meanwhile, engineering research projects, including one at the University of Missouri-Columbia, were already under way long before this week's bridge collapse to advance the science of bridge monitoring. At the school, work is being done on a large-scale sensor system that would be fastened to several concrete bridge piers below a span to alert officials about even the slightest tilting or swaying of critical piers supporting a bridge.
      • by canuck57 (662392)

        alert officials about even the slightest tilting or swaying of critical piers supporting a bridge.

        So was not this bridge already warned to politicians that it needed work? Do we need a 5000 DB whistle to make them wake up? The writing was on the wall.

        We will as a human race either evolve to vote past voting for hype turkey ass kissing politicians or someday they will foobar us all real big. Fortunately it was less than 30. Could have been worse. Happens in Canada, or shall I say Quebec too: http://e [wikipedia.org]

      • Re: (Score:3, Insightful)

        by donaldm (919619)
        Yes you can get sensors that will detect the slightest tilting or swaying of critical piers but the problem is that many bridges are designed to tilt and sway to a certain tolerance otherwise a ridged bridge would just crack under a small tremor or ever a surge of water. You would have to have sensors like this on all bridges and take into account the design tolerances of the bridge. You could do this cheaply in a country that has only a few bridges but when you have thousands of major bridges this is going
    • by igny (716218) on Friday August 03, 2007 @09:14PM (#20110023) Homepage Journal
      In the worst case scenario, the bridge closes itself.
      • by donaldm (919619)
        Unfortunately in the worst case scenario the bridge did close itself but it did it in a manner that caused people on the bridge to die. People who were lucky not to be on the bridge at the time of the collapse were safe although I would be quite sure they would be shocked. Even if the bridge had gates and they operated it would not help the people who were already on the bridge.
    • by canuck57 (662392)

      Would this system also have a feature to alert the local road authority, or in a worst case scenario close the bridge?

      It was already there, but no one was listening. How do you solve that?

    • Re:Barriers/Lights (Score:5, Insightful)

      by donaldm (919619) on Friday August 03, 2007 @10:59PM (#20110681)
      Taking into account all the factors that can cause a disaster is just about impossible. While it is possible to design something that is nearly disaster proof it can't be done with 100% confidence, because there are things that can occur that can be outside of the original design plan. Two simple examples are designing for a category 4 hurricane and then getting hit with a category 6 or designing for a richtor 5 earthquake and then getting hit with a richtor 7 earthquake.

      All that can be done is to have a flexible disaster prevention (eg. periodic bridge checks which actually were done) and a rescue program in place which from what I read about was quite good although to some who lost friends and relatives maybe not good enough. I would leave that to the investigation committee to comment on this.

      The problem with any disaster is it normally happens with little or no warning and sometimes so quickly people just cannot get out of the way. The question of "it could have been prevented" is rather mute after it has happened.
  • Is it not the easiest just to elect people who take care of things?

    At least from what I heared there are a lot of bridges in similar shape, but there's not much done about it.

    -- Stephan
    • Re: (Score:2, Funny)

      by Kagura (843695)
      Well, it didn't take long before a government contractor came up with a fool-proof way to secure government funds. Er, I mean, to prevent future incidents...

      Look at me, I'm cynical tonight. :)
    • Re:Political (Score:5, Insightful)

      by ktappe (747125) on Friday August 03, 2007 @11:20PM (#20110797)

      Is it not the easiest just to elect people who take care of things?
      If history is any judge, no, it apparently is not easy at all for the voting public to do that.
    • Re: (Score:3, Insightful)

      by SydShamino (547793)
      You mean like someone who would say "we need to raise taxes on, let's say, the wealthy (because they can afford it more readily) to fund infrastructure improvements across the country. Besides fixing all the aging infrastructure from the time when public works was still consider part of a great society, it will add hundreds of thousands of American jobs."

      It's called a traditional Democrat. They exist. Find one and vote for them, if that's what you prefer.
  • The bigger problem (Score:5, Insightful)

    by weak* (1137369) on Friday August 03, 2007 @08:11PM (#20109563)
    It was known well before the collapse that the bridge was in need of repairs. It seems that no public employee, elected or not, understands that prevention is better than reaction. New techniques to detect a heightened probability of failure are useful only if someone acts on the information once it is available.
    • by Anonymous Coward on Friday August 03, 2007 @08:38PM (#20109789)
      It was rated 'structurally deficient' [msn.com]:

      The Minneapolis bridge's deck, or driving surface, was rated in "fair condition." The superstructure was in "poor condition," and the substructure in "satisfactory condition."
      It looks like the 'satisfactory' substructure is what failed. Repairs to the driving surface and the trivial superstructure were ongoing. There was no indication from inspections that the substructure was in need of immediate repairs.

      The classification of structurally deficient means that either the surface, the superstructure, or the substructure was rated poor. In this case it was the superstructure which for this particular bridge did not provide support. A little bit of repairs to the superstructure and this bridge would have been cleared of its structurally deficient rating.
      • Re: (Score:3, Informative)

        by hey! (33014)
        Apparently, a few years ago they had found that the some of the steel had been distorted in unexpected directions. In retrospect this was ominous. It wasn't an acceleration of an expected wear process.

        This bridge was designed with a pair of steel arches which balanced on slender concrete piers on either side of the river. The load from the deck was transferred to the arches by a truss system: a network of triangles that reinforce each other. The problem with this design is that the failure of a single e
    • by GIL_Dude (850471) on Friday August 03, 2007 @09:09PM (#20109993) Homepage
      Get elected, then just try raising taxes to pay for something that might happen someday. Or, try to re-allocate funds from some bleeding heart program and see how far you get. People in general are not willing to fund repairs for things that might happen. It reminds me somehow of the little guy "Short Round" in Indiana Jones and the Temple of Doom jumping up and down on the footbridge yelling "strong bridge, see, strong bridge" just before starting to fall through the bridge. Obviously this is NOT FUNNY that this happened, but it just shows how people always want to think everything is fine right up until the time that it isn't fine.
      • by JonathanR (852748) on Friday August 03, 2007 @09:52PM (#20110287)

        )
        Get elected, then just try raising taxes to pay for something that might happen someday.
        Terrorism?
        • by ScentCone (795499)
          Terrorism?

          Which... actually HAS happened. Just like bridge collapses have happened. The difference is that there isn't so much malice involved in structural failure by way of aging infrastructure (as opposed to, say, flying airplanes into buildings or driving truck bombs up to otherwise perfectly fine structures).

          Bridges don't routinely pronouce their desire to alter your culture and spread Bridgelam by way of killing themselves. I think what we really need here is a sense of specifically which of the
        • Heh, over here in Australia most of the news stories mentioned it was not terrorisim in the first paragraph.
      • by ChePibe (882378) on Friday August 03, 2007 @11:51PM (#20110951)
        I had the opportunity to take a course on U.S. Intelligence and National Security from a gentleman who had worked on the Senate Intelligence Committee as a staffer for 10 years during the Cold War, specifically during the Carter and Reagan administrations.

        Discussing the politics of funding, he pointed out that it was easy - very, very easy - to get funding for new photo and signals intelligence sattelites, listening equipment, spy planes, and toys. He noted that, yes, some lobbying went on for these projects, but the lobbying isn't what swayed Congress - it was the new and shiny. They could all go home and say to themselves "wow, I put up a massive spy sattelite that can photograph buttons on Russian officers!"

        However, when it came to support for this equipment - analysts to look at the data they gathered, technicians to keep them running, maintenance facilities, etc. - they always came up short. In some instances, multi-million dollar pieces of equipment were purchased and deployed only to have the data they gathered analyzed only long after it was too old to be useful, assuming it was ever analyzed at all.

        I realize that this post is a bit off topic, but the problem of not supporting what is already there exists all through government. In the case of this bridge, shutting it down would have met with massive protest from all involved. Projects would have caused inconvenience, just as increased personnel staffing creates great cost for the government in many areas. People do the same thing all the time - buy new cars and toys, but never spend the money on maintenance, it all went to the toy. But if we build it or buy it we better be able to keep it in good shape.
        • Re: (Score:2, Funny)

          by king-manic (409855)

          I realize that this post is a bit off topic, but the problem of not supporting what is already there exists all through government. In the case of this bridge, shutting it down would have met with massive protest from all involved. Projects would have caused inconvenience, just as increased personnel staffing creates great cost for the government in many areas. People do the same thing all the time - buy new cars and toys, but never spend the money on maintenance, it all went to the toy. But if we build it
    • by plunge (27239)
      Americans like feeling heroic. Preventing tragedy isn't very telegenic or interesting. But letting things to go shit makes for damn good tv!
    • Re: (Score:3, Informative)

      by flyingfsck (986395)
      Well, people were actually busy doing repairs when the bridge collapsed. It is possible that the hammering of the repair activities contributed to or hastened the collapse.
      • Re: (Score:3, Interesting)

        by cheater512 (783349)
        They were repaving it. Not doing structural repairs.
        The media likes the hype of saying 'it was under repair at the time'.
    • by penix1 (722987) on Friday August 03, 2007 @10:58PM (#20110677) Homepage

      It seems that no public employee, elected or not, understands that prevention is better than reaction.


      No it isn't...

      This may seem callous and cold in the wake of this incident but in fact it is cheaper (hence "better") for the state to react sometimes than to mitigate a hazard. It is simple economics. The federal cost share is 75% federal, 25% state. In catastrophic events, that split drops to 90 / 10, or at the discretion of Congress, 100% federal (Katrina is 100% federal). If the hazard you are attempting to mitigate would cost more than if it fails, then it is cheaper to let it fail. Of course, you run the risk to life and property when you do this so it is a huge gamble.

      States are cash strapped with the thousands of "unfunded mandates" the federal government places on them. Everybody want services but don't want to pay for them in higher taxes. Then you get pandering politicians running on "lower taxes" campaigns further reducing a states ability to operate properly. It is a wonder it took this long for something to happen.
    • Re: (Score:3, Insightful)

      by GoofyBoy (44399)
      >It seems that no public employee, elected or not, understands that prevention is better than reaction.

      1. Its every elected and non-elected public service employee understanding that you NEVER want anything to make the news in a negative way, regardless how correct the information is. This goes for dog-leash laws to fire services. Preventing this from happening is almost their number 1 job.
      2. Regardless of what your perception is, there are some serious employees at any government. How many profession
  • Put some wireless sensor nodes across the bridge and sense for unusual vibrations between the intersections. That's what Wireless Sensor Networks is all about. When there is a crack the vibrations will cause a signal to be sent out.
  • How about this? (Score:4, Insightful)

    by rolfwind (528248) on Friday August 03, 2007 @08:15PM (#20109597)
    Step 1: Stop nation building OTHER COUNTRIES
    Step 2: Start nation bulding OUR COUNTRY
    Step 3: No step 3. It doesn't have to be so complicated.
    • by canuck57 (662392)
      Makes a lot of sense. Think, instead of saving the middle east, let them knock each other off. Let them buy the bombs for profit. Turn it to bridge reconstruction. No, I am not kidding, I though this parents post was accurate and sane. Why spend billions on Neanderthals when you can build at home.
      • Makes a lot of sense. Think, instead of saving the middle east, let them knock each other off. Let them buy the bombs for profit. Turn it to bridge reconstruction. No, I am not kidding, I though this parents post was accurate and sane. Why spend billions on Neanderthals when you can build at home.

        Each American who thinks the invasion Iraq is "saving" the middle east is an active contributor of why the US has had a sharp decline in buying power and the general decline in common sense and intelligence. If the
    • It's not a zero-sum game. We're a superpower for Christ sake! There's no reason for us to not do both. And both, my I remind you, are of national interests. The idea that we can do only one or the other is short sighted.

      Second point. The bridge problem was first spotted in 1990. That's 17 years ago. Also, (like New Orleans) the public infrastructure funding falls squarely at the state level, NOT federal.
      • by rolfwind (528248)

        We're a superpower for Christ sake!

        That title will be lost fast the way we are tossing money around.

        There's no reason for us to not do both.

        Um, let me see. We are borrowing about $3 billion dollars a day, mostly from Chinese and Japanese investors, to do this nation building. Also, we are robbing our citizens to give to their citizens for some unfathomable reason. They hate us more and more every passing day. Our troops are getting killed. The longer we stay, the more entrenched Al-Queda becomes in Ira

  • by Thorrablot (590170) on Friday August 03, 2007 @08:16PM (#20109609)
    I'm a Twin Cities resident (local name for Minneapolis/St. Paul), and have taken this bridge hundreds of times, as well as biked along trails on the riverbanks below it. It was never an attractive bridge, but certainly showed no obvious signs of problems. I was shocked to learn that a good friend of mine was told by a structural engineer two weeks ago that he "always avoids driving on that bridge during rush hour" - apparently the engineer had already read/heard something that we're just finding out.

    This smacks of criminal negligence - complete catastrophic failure in 4 seconds could not have been an undetectable condition.
    • by Paktu (1103861) on Friday August 03, 2007 @08:23PM (#20109663)
      There's conflicting reports about it. The Feds inspected it a few years ago and said it was in immediate need of repair, but the state sent in people who claimed it would be viable until 2020. While it might appear that the state just didn't want to spend money, keep in mind that Minnesota has the third lowest percentage of structurally deficient bridges [statemaster.com], so it's not like there were other major priorities that were sucking up funding.
      • by moosesocks (264553) on Friday August 03, 2007 @09:34PM (#20110161) Homepage
        Likewise, you're not exactly going to be able to attract funding to fix or replace the bridge if you're going around telling everybody that everything's just peachy.

        Personally, I sort of doubt that this could have been prevented. It's one of those one-in-a-billion sort of odds that unfortunately caught up with us...

        I'm more than a bit irked at the media for taking the "structurally deficient" term, and plastering it all over the news without a very clear understanding of what it means. There's no cause for a panic or a rucus -- our bridges are no more dangerous today than they were last week. Hell, we don't even know what caused the bridge to collapse, and ordering all sorts of emergency inspections (which has been done in many many states so far) is pointless considering that the bridge that collapsed was previously deemed to be safe on multiple occasions.

        Of course, other recent incidents such as the con edison steam explosion in NYC reek of criminal negligence.
        • Re: (Score:3, Informative)

          by DerekLyons (302214)

          I'm more than a bit irked at the media for taking the "structurally deficient" term, and plastering it all over the news without a very clear understanding of what it means.

          Here in WA, the WA DOT has essentially admitted that "structurally deficient" [kitsapsun.com] is a scare word used to boost priority in asking for federal funding.
          • Back home, the one-lane farm bridges in my town are all "structurally-deficient" despite there being absolutely nothing wrong with them.

            In fact, spending money to upgrade them to two-lane bridges would be stupid.
        • My governor came out and told everyone not to worry. Apparently, even though my state has particularly low rated bridges, it is not a problem because the inspections are "largely up to date."

          He literally referred to them as being "largely" up to date. As in, not "fully" up to date. Nor even "mostly" up to date. But, at least "some," and possibly as many as "many" though not necessarily more than half, have up-to-date inspections. Don't even ask about the actual maintenance.

          And the great irony is that w
        • Re: (Score:3, Interesting)

          by king-manic (409855)
          Likewise, you're not exactly going to be able to attract funding to fix or replace the bridge if you're going around telling everybody that everything's just peachy.

          Personally, I sort of doubt that this could have been prevented. It's one of those one-in-a-billion sort of odds that unfortunately caught up with us...

          I'm more than a bit irked at the media for taking the "structurally deficient" term, and plastering it all over the news without a very clear understanding of what it means. There's no cause for
        • by SETIGuy (33768) *

          Personally, I sort of doubt that this could have been prevented. It's one of those one-in-a-billion sort of odds that unfortunately caught up with us...

          It's more like one-in-a-few-thousand odds. We don't have a billion bridges in this country, and a collapse seems to happen every couple years or so. And like it or not, it is a political calculation regarding how much we are willing to spend to prevent such things. Thus far the answer is that we are willing to spend enough that we don't have a collapse

    • by Vellmont (569020) on Friday August 03, 2007 @08:32PM (#20109731) Homepage

      This smacks of criminal negligence - complete catastrophic failure in 4 seconds could not have been an undetectable condition.

      You have way to much confidence in science and technology. I think it's certainly possible that the inspections done didn't detect the problem with the bridge. Science isn't perfect, and there's always assumptions and things no one knows.
    • by MtViewGuy (197597)
      Two things I immediately noticed that made me openly wonder why this bridge was so vulnerable:

      1) The spindly structure makes it apparent that the whole thing will come down even with one minor structural stress problem.

      2) The surprisingly small size of the bridge supports.

      I personally expect the replacement bridge to be a writ large size version of 10th Avenue Bridge nearby with its thick, concrete structures.
  • by ChromeAeonium (1026952) on Friday August 03, 2007 @08:17PM (#20109619)
    As the old phrase goes, an ounce of prevention is worth a pound of cure. The technology's nice and all, but I'd saw the trick is getting people to look into this sort of thing, and take action, beforehand. I say this because in my area there was an old bridge that many people used regularly, however, it was a well known fact that it was deteriorating. The city, however, didn't want to spend the money to fix it, and it was years before anything was done (despite the fancy new road nobody wanted or needed that was built just minutes away). That bridge could have possibly collapsed, and everyone knew it. This new technology might make detection easier, but as long as the almighty buck is king, no amount of technology can compensate for human nature.
    • by Detritus (11846)
      We could take an idea from Hammurabi, and drop several hundred tons of concrete and steel on the heads of the government officials responsible for the safety of the bridge.
  • Like building structural redundancy into the bridge to begin with?
    • by Paktu (1103861) on Friday August 03, 2007 @08:29PM (#20109711)
      While it's easy to ask "why didn't they just make it redundant?", there are reasons behind these decisions. Please take a look at this link: http://www.visi.com/~jweeks/bridges/pages/ms16.htm l [visi.com]

      There's a lot of good info there, but here are the cliff notes:

      A University of Minnesota Civil Engineer in a report to MN-DOT recently noted that this bridge is considered to be a non-redundant structure. That is, if any one member fails, the entire bridge can collapse. A key factor is that there are only four pylons holding up the arch. Any damage to any one pylon would be catastrophic. The textbook example of a non-redundant bridge is the Silver Bridge over the Ohio River. It failed shortly before Christmas in 1967 resulting in 46 deaths. A single piece of hardware failed due to a tiny manufacturing defect. But that piece was non-redundant, and the entire bridge collapsed into the icy river. Today, bridge engineers design bridges so that any single piece of the bridge can fail without causing the entire bridge to collapse. It is tragic that the I-35W bridge was built a few years too early to benefit from that lesson.

      • IIRC, the I-35 bridge was built in 1967, so the designers/builders weren't as painfully aware of the importance of redundancy as after the collapse of the Silver Bridge.

        A similar thing happened in California wrt the 1971 Sylmar earthquake. Several bridges of the newly completed I-5 came down, the cause was found to be lack of hoop strength in the re-bar inside the column. Columns built after that used helically wound rebar to keep the column intact under seismic loading. The need for retrofitting was dri

  • ironic (Score:2, Informative)

    there's a rant i read a few days ago from a what seems to be a bitter old time engineer who says that ancient styles of bridge design fare better than more modern ones because of redundancy: if something fails, the damage is localized, rather than the whole bridge going because of just one of many of its elements. he points to something called "value engineering"- aided by computer analysis, that is the source of this kind of bad nonredundant bridge design that was the I35W bridge

    what's ironic is that moder
    • Re: (Score:3, Insightful)

      by Ron Bennett (14590)
      Some may be interpret his comment about NY WTC 1 & 2 as over the top, but he's right on ... they too were an example "value engineering", to borrow a phrase from above, while having redundency for their outside shells, did NOT for the floor slabs themselves; each floor was designed to around 3x expected load, but that's of little to no help in a "pancaking" scenerio in a tower that had well over 100 floors...

      Also, some of the other "value" decisions made during WTC 1 & 2 construction are laughable b
    • Re: (Score:2, Insightful)

      by dwhite21787 (166571)
      from what I recall, the WTC was well engineered. The heat retardant on the structural steel was applied badly, and the beyond-tolerance damage of the jumbo jets managed to take out the planned redundancy. I wouldn't put the WTC in this category.
    • Re:ironic (Score:4, Insightful)

      by Alastor187 (593341) on Friday August 03, 2007 @09:36PM (#20110189)
      Are sure that was written by an engineer?

      He says look at the WTC, it collapsed because of the lack of redundancy.

      What?

      Seriously, the building was hit by 150,000 lb aircraft carrying 20,000 gallons of flammable liquid. It was obviously never designed to withstand that kind of structural complication.

      However, for a minute lets say someone had enough foresight to add "resistance to impact from commercial aircraft" into the structural requirements. Why stop there? What about earthquakes, hurricanes, tornados, tsunamis, or meteorites?

      Where do you draw line? How much cost can you tolerate?

      It is not engineering that is overly concerned with cost to benefit ratios, that responsibility falls on management and/or accounting. If engineering comes up with two designs for a bridge, where one is under budget and lacks redundancy and the other is over budget and but incorporates redundancy, it is management or the customer that must decide what is most important.

      Now some people may say that engineering has an ethical responsibility to build the best product, which may be true. But how does one do that, by quitting their job every time that don't get their way? Or by building the better a better product with the lesser budget, that is working for free?

      While I agree that modern engineering has a lot less design tolerance. I think this is thanks to a better understanding of physics as well as better tools. So it is now possible to safely design bridge with a poor failure mode because we 'better' understand what drives the failure (I am not saying that poor failure modes are better).

      In this case I think the inspection process is more suspect than actual design. I think everyone would agree that the design had areas of concern. But no design is perfect and all bridges will eventually fail. That is why they are inspected on regular bases. How is it that this bridge was inspected in the last few year and no critical issues were found? Doesn't that mean that a better inspection process is needed?
      • by adolf (21054)
        Where do you draw line? How much cost can you tolerate?

        I suck at math, so I'm sure that I'm expressing this wrong. But I'll try to answer your question anyway:

        B / (W + F + H + P) = T
        • B is the number of buildings, bridges, or other structures in the USA which generally could use (or could have used) more redundant engineering, whether because of their intrinsic or functional value, the potential for lost life, or the structures' ability of to frighten grown, rational adults for years to come in the event of
      • However, for a minute lets say someone had enough foresight to add "resistance to impact from commercial aircraft" into the structural requirements.

        That's thing - they did, which both you and the 'old engineer' seem to be unaware of. (However the commercial aircraft of the era were much lighter - and the analysis only took into acount impact damage, not the subsequent fire.)

        Why stop there? What about earthquakes, hurricanes, tornados, tsunamis, or meteorites?

        Almost certainly the WTC desig

      • All that jet fuel rapidly burned off, far before the 1 and 2 towers collapsed.

        What most likely caused, according to experts, the 1 and 2 towers to collapse was structure failure of the connections of floor struts due to the heat of furnishings, etc burning (note again, the jet fuel rapidly burned off in the first few moments) and heating the steel, which was poorly insulated...

        The floor struts warped, floor connections to the curtain wall failed, causing floors to fall onto the floor below them - now that a
    • Re: (Score:3, Interesting)

      by ucblockhead (63650)
      One big reason Roman bridges lasted so long is that the Romans had no clue how to build a bridge that was strong "enough". Because they were ignorant of the math and engineering required, they instead just built as strong as possible, damn the cost. This was, of course, much, much stronger than strong enough to last a few decades. We, with our modern engineering, can build things that are strong "enough", and thus, don't last near as long and are generally weaker. But we save lots of money.

      Until someone
      • Re: (Score:3, Insightful)

        by quax (19371)
        Slapdash. If you calculate that your empire lasts forever the most economic way to build is to engineer structures that last forever.
      • by joshuac (53492) *
        ...nevermind that after about 2000 years, the only bridges that would remain for us to see would be the best examples.

        I bet the average Roman bridge that existed during the height of the empire isn't as good as what examples are still standing for us to look at.
      • by donaldm (919619)
        The Roman engineers had a very good grasp of civil engineering and maths since a good deal of knowledge was got from Greece and improved on. They did not just build as strong as possible and hang the expense since a bridge building project still had to be paid and accounted for by the province it was being built in unless it was of a strategic nature where the cost would be shared. Much like how our modern societies work.

        You did not mention slaves and that is good since most of the Roman roads and bridge
        • How well can you really understand why a bridge stands up without even Newton's understanding of physics and math?
      • by TheLink (130905)
        I bet the other reason is you only see the ones still standing ;).
    • Re:ironic (Score:5, Insightful)

      by macaddict (91085) on Friday August 03, 2007 @10:53PM (#20110647)
      disaster waiting to happen, just like the World Trade Center

      A disaster? WTF do you have to do to be considered a success for this guy?

      A fuel-laden commercial jet slams into a 110 story building (x2) and a little less than 3,000 people died.

      The buildings could have collapsed immediately and killed, what, about 20,000 people? But both stood long enough (56 minutes and 102 minutes) to evacuate most of the occupants. Sounds like a pretty damn successful building design to me.
    • by joshuac (53492) *
      ---snip ...wasn't enough "give" for the shaking due to the quake. Two lives were lost - one by a woman who tried to drive her car across the gap and who would have survived had she waited for help. However, the rest of the bridge remained and will be used until this fall when it is destroyed...
      ---snip

      Wow. This really stands out to me for some reason; the one fatality on the Bay Bridge wouldn't have changed had she "waited for help".

      A quick google:
      http://www.sfmuseum.org/hist2/presidio.html [sfmuseum.org]
      (ctrl-f for "Moal
    • by Temporal (96070)
      What funding do you propose we cut in order to find money to make bridges ever-so-slightly safer? Shall we cut funding for schools? Reduce the police force? Neglect other roads in need of repair?

      Bridges in the western world already have an extremely low failure rate. Reducing it further would require an enormous investment for almost no gain. There are much better ways that we can spend that money.
      • What funding do you propose we cut in order to find money to make bridges ever-so-slightly safer? Shall we cut funding for schools? Reduce the police force? Neglect other roads in need of repair?

        Bridges in the western world already have an extremely low failure rate. Reducing it further would require an enormous investment for almost no gain. There are much better ways that we can spend that money.


        Take money from various projects like the multi billion dollar war, or various graft projects awarded to Lockhe
  • by viking80 (697716) on Friday August 03, 2007 @08:31PM (#20109723) Journal
    Usually "The Science of Bridge Collapse Prevention" is called "The Science of Bridge Construction"
  • by weak* (1137369) on Friday August 03, 2007 @08:40PM (#20109801)
    ...that someone we're paying with our tax dollars either fucked up or didn't care. Now what? Can we simply vote for better people? Of course not: history demonstrates conclusively that these better people don't exist, don't want the job, or go unnoticed (largely because the general public doesn't have the time or the means or the interest to assess the competence of prospective officials). So what do we do to put qualified people into positions responsible for our welfare, and hold them accountable once they're there?

    It's a hard question, so I think I'll just ignore it, in light of the sad truth that a month from now, no one (who doesn't have a personal connection to the tragedy) will care. To hell with "doomed to repeat it."

  • My technique (Score:5, Interesting)

    by TopSpin (753) * on Friday August 03, 2007 @08:41PM (#20109807) Journal
    I have a method of Minnesota infrastructure maintenance that can assure sound bridges. My technique involves billing the Twins owner for the $392 million of government revenue (collected via a sale tax hike [wcco.com]) being used to fund the new $522 million baseball stadium. My technique also involves continuing to dash the hopes [startribune.com] of Minnesota football fans for a new government funded $0.5 billion football stadium. Instead, let the team owners rely on sports geek revenue to fund their stadiums, and misappropriate the tax revenue into infrastructure.

    On the other hand, perhaps it isn't necessary to piss off all the Minnesota sports geeks (read: voters) and instead utilize the $2 billion dollar state surplus [publicradio.org] to deal with the states bridges. But alas, there are voters to buy [ncsl.org] with that money.

    This is about the priorities of the citizens of a staggeringly wealthy nation being focused on everything but the infrastructure.

    • by couchslug (175151)
      What a terrible idea!
      Look at the benefits New Orleans got by attracting the Saints instead of spending that money on tacky flood control...
      • by TopSpin (753) *

        Look at the benefits New Orleans got by attracting the Saints instead of spending that money on tacky flood control...
        Peace Brother. I hear you.

  • by Junior J. Junior III (192702) on Friday August 03, 2007 @08:45PM (#20109833) Homepage
    What a joke. We've been building bridges for the whole of recorded history, and some of them have stood for much of that time. We have the capability and have had it for centuries if not millenia to build a bridge that doesn't fall. We just have to pay attention and maintain what we build. It's not THAT hard.

    Maybe if we stop worrying about falsely exaggerated threats like terrorism and manufactured problems like the war on in Iraq, we'll have more than adequate resources to build a really damn good infrastructure, and then things like the bridge collapse in Minneapolis and the steam main explosion in NYC wouldn't ever happen.
    • Re: (Score:3, Insightful)

      by petermgreen (876956)
      We've been building bridges for the whole of recorded history, and some of them have stood for much of that time.
      and i'm sure many of them haven't

      sure if you build a stone arch accross a narrow vally in an area with no sismic problems then it will stay up for a very long time, especially if the area is too dry for much plant life. However it will be very expensive for the ammount of utility it gives.

      but of course we want more, we want our longest bridges longer, we want all our bridges able to stand being p
    • Re: (Score:3, Interesting)

      by MichaelSmith (789609)

      We just have to pay attention and maintain what we build. It's not THAT hard.

      I used to work for the state highway authority, working on traffic signals. When I was there the entire bridge department were made redundant and replaced by contractors. No matter how much you document these things, you still need continuity from one generation to the next. The old guys have to be around to tell the young guys to look out for this and that, or it may cause problems.

      But it is cheaper to outsource.

      • used to work for the state highway authority, working on traffic signals. When I was there the entire bridge department were made redundant and replaced by contractors. No matter how much you document these things, you still need continuity from one generation to the next. The old guys have to be around to tell the young guys to look out for this and that, or it may cause problems.

        But it is cheaper to outsource.


        I find the notion of contractors comical. basically you pay 3 times the amount to them so that i
  • Stop building goddamn sports stadiums and zoo exhibits and concentrate on what's important.
  • Maybe we should go back to stone and mortar bridges. Today's bridges in America don't last very long and they never meet the roadway without a bump or a dip. Many are obsolete or too small by the time they are even completed. Modern engineering doesn't stand a chance to the builders of yesterday.

    Take a look at the famed Rialto Bridge in Venice, Italy. This bridge was built almost 500 years ago and still stands even after numerous earthquakes in the region.

    Then there is the stone bridge in the Czech Repub
    • Re: (Score:3, Informative)

      by r_jensen11 (598210)
      Those bridges weren't constructed with having nearly 150K vehicles regularly going over them every 24 hours. The ancient civilizations had marvelous constructions, no doubt. There's no structure built in the past 100 years that will last as long as half of what was build in Rome lasted. However, we abuse our infrastructures a hell of a lot more than they did.
    • Maybe we should go back to stone and mortar bridges. Today's bridges in America don't last very long

      Maybe you should learn a little bit about bridges - over 80% of the major ones are at least forty years old, and a good number are getting pretty close to the century mark. A handful are well past the century mark.

      Equally, there are more than a few stone bridges in Europe that have collapsed (some within decades of construction - at least one in mid construction).

      One must ask why wit

  • A massive bridge collapsing underneath you is terrifying, e.g. a source of terror. We could close the thousands of bridges in the US that, like the 35W bridge, are rated "structurally deficient", in the name of preventing "another 8-1". This might help expedite funding to rehab these bridges, and fighting the "terror" of unsafe bridges would fit with our current national priorities.

  • What do they have about the _SOCIAL_ science of politicians who say, "Well, it probably won't fall down on _my_ watch so I'm going to be a 'tax-cutter'"?

    Yes, a little testy. From the Cities and watched it from first rumor until dark on the MythTV box. Burned a DVD of the lot. Used to work at U of M and commuted from near South Minneapolis. Remember the bridge well.

    Dumb bitch of the Transportation Commissioner was on the news 10 minutes ago. I just looooved her line about, "Don't any of you accuse me of
  • If you put your ear on a train track, you can hear a train approaching from far away

    Has anyone done this before? The bumper sticker on a train reads If you can hear me, your head will be cut off.

    Feel a rail on a track. Long after a train has passed, the track is still hot. I put my ear to the track, but could not hear the train through the rail. This was a rail that has its segments bolted for high speed trains. However, I did hear the train in the air, ear not on rail. The train was a high speed train with
  • This is a parking garage story.

    About five years ago, a chunk of cement about the size of a football fell on a buddy's car in the parking garage. At that time, the garage was a few years old.

    Engineers were called in and placed acoustic monitors all over the place on many of the beams. Then drove vehicles over them on a couple of weekends.

    Evidently acoustics found anomalies. They determined that the interior cabling was insufficient.

    After a couple of different fix attempts engineers decided on the following.

    A
  • While there seems to be ways to "listen" and detect potential problems with bridges, I doubt that the bureaucracy of government will ever make the remedies work.

    Coupled with my government's incompetence, bigotry and history of wasting money (read Iraq), it will surely be a wonder if this setup ever works. God help us!

  • Acoustic emissions detection systems, which listen for the sounds of metal snapping on structures are already are being sold and fitted.

    Metal snapping? Why not just listen for motorists screaming? I assume these actually listen for some kind of metal stress sound, rather than actual failure? No, I didn't read TFA, so feel free to ignore me.
  • by michaelmalak (91262) <michael@michaelmalak.com> on Friday August 03, 2007 @11:12PM (#20110763) Homepage
    From yesteday's New York Post [nypost.com]:

    A 2001 evaluation of the bridge, prepared by the University of Minnesota, reported that there were preliminary signs of fatigue on the steel truss section under the roadway, but no cracking.

    The report said there was no need for the Minnesota Transportation Department to replace the bridge because of fatigue cracking.

    But a May 2006 report by the department noted that inspectors saw fatigue cracks and bending of girders along the span's approaches.

    I.e., in 2001 they barely passed it because they said, "at least there's no cracking." In 2006, they saw cracking but kept the bridge open anyway. At minimum, they should have closed it to heavy truck traffic, scrapped the idea of doing heavy construction (repaving) on the bridge, and started construction of a replacement immediately.

    For more info, see today's Minneapolis Star Tribune article [startribune.com].

  • benefit analysis (Score:3, Insightful)

    by fermion (181285) on Friday August 03, 2007 @11:25PM (#20110831) Homepage Journal
    What all this misses is there are armies of accountants wieghing risks of an accident against costs to prevent the accident. The system is not perfect, but it is the one we have, and the one we will likely continue to have. Most of the technology in this article is not new. It simply requires a higher budget. Certainly, we could spend money to better detect fatique, but in a worl or limited resouces, is the best use of money to reduce risk?

    Perhaps if this accident killed hundreds of people, and resulted in a settlement of tens of billion of dollars, then the landscape might shift. Or, if like automobile manufacturers of past, we find that the accountants are making fundamental compromises of safety merely because the cost of a human life is less than the cost of implementing the features.

    About the only thing that does not fall under this risk analysis is the military. This is why they can get away with spending 100 billion dollars a year with only a discrediting italian letter to substantiate the claim, a letter not even endorsed by the US government, but by the british. Otherwise we have to use the imperfect system of where to spend our money and where not to. I don't suppose that we are going to see an increase in taxes, or the removal of the new corporate welfare incorporated a few years ago, or a reduction in say in money spent on standardized test for kids. i think we can have anything we want if it is really worth sacrificing.

  • 1. Engineer tells politician bridge needs fixed.
    2. Politician tells engineer "Ok, fix it".

    Sadly, the more common scenario is...

    1. Engineer tells politician bridge needs fixed.
    2. Politician is too busy bragging about his "low tax government" to listen.
    3. Bridge falls over.
    4. Politician calls an official enquiry, staffed by his cronies, which blames the engineer.

  • ...I think of Computer World!

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