KTVU and the Bridge -- how to luck out...
Pete
Thr KTVU news crew must be patting each other on the back tonight!
They just happened to have Sal Castaneda and crew heading home to SF
and on the bridge as it was being closed, so they were able to report
from the failure area itself. Got some nice closeups of the crashed
cable and crossbar!
All the other channels seem to have had to be content with long distance
shots (and KTVU got moved back too by 10 pm).
Aside from that, of course, it's a mess. And you know somebody is going
to be in trouble...
-- Pete --
--
============================================================================
The address in the header is a Spam Bucket -- don't bother replying to it...
(If you do need to email, replace the account name with my true name.)
============================================================================
Alan
>
>Thr KTVU news crew must be patting each other on the back tonight!
>They just happened to have Sal Castaneda and crew heading home to SF
>and on the bridge as it was being closed, so they were able to report
>from the failure area itself. Got some nice closeups of the crashed
>cable and crossbar!
>
>All the other channels seem to have had to be content with long distance
>shots (and KTVU got moved back too by 10 pm).
It looked like KGO/7 was pretty much in there, too. A camera close in
looking at the cable parts, and a helicopter looking at the bridge, as well
as people and cameras at each end.
>Aside from that, of course, it's a mess. And you know somebody is going
>to be in trouble...
I would expect that there will be some engineering questions to be
raised.
Alan
gvk2
> Thr KTVU news crew must be patting each other on the back tonight!
> They just happened to have Sal Castaneda and crew heading home to SF
> and on the bridge as it was being closed, so they were able to report
> from the failure area itself. Got some nice closeups of the crashed
> cable and crossbar!
>
Yes, and Gene Burns was lucky to be able to call up Bill Wattenburg
for his engineering ideas about the possible reasons for the bridge
failure.
Too bad for the other radio stations, they had to rely on "structural
engineers" from ba.broadcast and other such Wikipedia schooled
experts.
leansto...@democrat.com
Oh please, are you serious that Dr. W was put on the air for the
bridge failure? Last time I checked, he isn't a structural engineer.
David Kaye
> I would expect that there will be some engineering questions to be
>raised.
Oh, that's okay. Bill Wattenburg will have all the answers. I'm sure KGO
has already put him on the air at least once.
--
"You're in probably the wickedest, most corrupt city, most
Godless city in America." -- Fr Mullen, "San Francisco"
VanMan
structural engineering. He actually asked the good Dr. to make some
calls, to see if he could provide better information that that being
reported on KGO news
The Dr., of course, contributed absolutely nothing to the program.
For goodness sake, Gene, and your producer, get some contacts with
some real experts at the local universities and agencies who you can
call when the next accident happens.
David Kaye
>It amazed me too that Gene Burns called on Wattenburg as an expert in
>structural engineering.
Oh my gosh...I meant that as a joke. A joke. A joke....
David Kaye
>It amazed me too that Gene Burns called on Wattenburg as an expert in
>structural engineering. He actually asked the good Dr. to make some
>calls, to see if he could provide better information that that being
>reported on KGO news
As long as we have doctors around, I suggest that next time Gene Burns call up
Dr. Marty Nemko or Dr. Dean Edell to talk about structural engineering.
VanMan
"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."
KGO need to get this professor on for an hour.
Patty Winter
In article <7d588c56-3954-40c8...@k13g2000prh.googlegroups.com>,
VanMan <ttux...@gmail.com> wrote:
>This from AP:
>
>"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."
>KGO need to get this professor on for an hour.
He's been on KGO and other stations a lot. I'm not convinced that
he's the best one to be interviewed, since he's been against the
rebuild all along. Is he in fact the best available expert outside
of Caltrans, or is he someone with an agenda he wants to promote?
I'm not sure, but I get skittish when all the stations interview
the same person over and over. To me, it looks like the stations
are taking the easy way of putting on the air whoever contacts
them, rather than going out and researching a range of experts.
Patty
Neil
The professor was just on with Michael Krasny on KQED in the 9:00-9:30
half hour. (As was Caltrans spokesman Bart Ney.)
Krasny brought up the same point, that Astaneh-Asl and some colleagues
at Cal submitted an alternate bridge design proposal, which Caltrans
didn't select. The implication being that he might have an axe to
grind in his pointed criticism of the band-aid approach Caltrans took
with the Labor Day repair. However, events have shown him to be right
insofar as the repair turned out not to be adequate.
Neil
<leanstothel...@democrat.com> wrote:
> On Oct 28, 1:09 am, gvk2 <gvk2...@yahoo.com> wrote:
> > On Oct 27, 10:34 pm, neverl...@GOODEVEca.net (Pete) wrote:
> > Yes, and Gene Burns was lucky to be able to call up Bill Wattenburg
> > for his engineering ideas about the possible reasons for the bridge
> > failure.
>
> bridge failure? Last time I checked, he isn't a structural engineer.
The problem, IMHO, is not that Wattenburg isn't a structural engineer.
(Lots of us who have engineering degrees in other disciplines have
taken some rudimentary course in mechanical and/or civil engineering
-- you know the old saying that in the land of the blind, the one eyed
man is king -- and could speak in generalities with a modicum of
technical insight.) My issue is that Dr. Bill doesn't add much to the
radio program as an *engineer*, because he comes across as the same
attack dog talk host as he does on his weekend shows.
The situation calls for getting third party experts from reputable
universities or engineering design firms, unassociated with the
specific situation, who can speak lucidly to the problem at hand,
without any axe to grind. This is where NPR (as opposed to 'QED, the
local station) performs so much better than the local guys. Again,
IMHO.
leansto...@democrat.com
I studied statics and dynamics in college, but wouldn't attempt to
speak with authority this incident. Dr. Bill doesn't know when to shut
up.
I've had some experience in designing sensor conditioning circuits. It
is possible to make "smart" structures that can sense their impending
failure. The classic case is sensing bearing noise. It's an offshoot
of NDT, if you are familiar with that.
leansto...@democrat.com
Both of those doctors are smart enough to decline to comment outside
their field of expertise.
Incidentally, Dr. Dean is on vacation again, i.e. the shows are
reruns. At one time they would alert the caller early in the show that
it is a rerun and not to call. I have an excellent memory for spoken
word, so know early in the game that it's a recording. I caught one
rerun a few months back where I can tuned in towards the end of the
show and caught Heather saying it was recorded.
leansto...@democrat.com
Not to be adequate is putting it mildly. Structures are engineered way
beyond the normal wear and tear they should receive. You may recall
the Golden Gate Bridge "celebration" where they shut it down to
traffic and allowed people to pile onto it, somewhat flattening the
shape of the bridge. It was after the fact that Caltrans decided to
check if the bridge was safe under those conditions. Fortunately, much
like the 747, the GGB has a ton of margin.
Peter
<leansto...@democrat.com> said:
> I studied statics and dynamics in college, but wouldn't attempt to
> speak with authority this incident. Dr. Bill doesn't know when to shut
> up.
The "fix" ... I would term it a "hack" ... was to install two
identical, or nearly identical, "saddles" at the top and the bottom of
the cracked/failing "eye bar", and to secure these with tension members.
Yet, that "fix" was retained in-place not by eight members in tension,
but by only four.
Hence, there was no reduncancy in that "fix".
And, by the usual laws of finite element design, if one tension member
failed, then the other three would no longer be in tension, or these
would be overstressed in tension, and these would fail, as they did,
indeed, do.
Cables held in tension (of the general type as used in pre-stressed
concrete structural systems) would have been an ever so much better a
"fix" than would be (past tense) steel rod, threaded at each of the
ends, and tensioned by a simple threaded nut.
But, I am not a registered professional S.E., although I did develop
and test CAE (computer-aided engineering) tools for finite-element
design, and perhaps someone who is a licensed S.E. within California
would care to comment.
I am advised that there is, within this "extended community", such a person.
Hmmm.
--
Peter Haas - Monterey Bay, California
+1 831 GArden 6-5482
Should you quote, please quote only the relevant text!
Bob Summit
speak with authority this incident. Dr. Bill doesn't know when to
shut
up."
Oh for crying out loud. Your shoes a little wet today? Like you Gene
couldn't pour piss out of a boot if the instructions were written on
the heel so he called Bill to see what information Bill had gleaned
from his sources and to help interpret the news reports coming in. He
didn't ask Bill for a instant structural analysis. Bill was probably
called upon for his ability to explain technical information to non-
technically oriented lay people. Next time Gene should consult with
one of the Four ba.broadcast Amigos. They seem to have the answers to
everything.
VanMan
tonight. He recommends that the bridge be shut for ten days while an
extensive examination of all the tie bars be made, and proper repairs
carried out.
spamtrap1888
> On 2009-10-28 13:33:25 -0700, "leanstothel...@democrat.com"
> <leanstothel...@democrat.com> said:
>
> > I studied statics and dynamics in college, but wouldn't attempt to
> > speak with authority this incident. Dr. Bill doesn't know when to shut
> > up.
>
> The "fix" ... I would term it a "hack" ... was to install two
> identical, or nearly identical, "saddles" at the top and the bottom of
> the cracked/failing "eye bar", and to secure these with tension members.
>
> Yet, that "fix" was retained in-place not by eight members in tension,
> but by only four.
>
> Hence, there was no reduncancy in that "fix".
>
> And, by the usual laws of finite element design, if one tension member
> failed, then the other three would no longer be in tension, or these
> would be overstressed in tension, and these would fail, as they did,
> indeed, do.
>
> Cables held in tension (of the general type as used in pre-stressed
> concrete structural systems) would have been an ever so much better a
> "fix" than would be (past tense) steel rod, threaded at each of the
> ends, and tensioned by a simple threaded nut.
>
> But, I am not a registered professional S.E., although I did develop
> and test CAE (computer-aided engineering) tools for finite-element
> design, and perhaps someone who is a licensed S.E. within California
> would care to comment.
>
> I am advised that there is, within this "extended community", such a person.
>
Although a mere HS graduate, I can't resist putting in my 2c:
Are those eyebars never in compression? That would make cables kinda
useless here. The cables are designed to keep concrete in compression,
naturally, at which concrete excels.
leansto...@democrat.com
Yet another person with a reading comprehension problem. I merely
suggested Gene consult with someone qualified rather than Dr. Bill.
Why the personal insults?
leansto...@democrat.com
Somebody ought to take the next step and install real time monitoring
equipment.
<http://www.ambiosystems.com/index.php/Demonstrations-and-Application-
examples/Bridge-10-2007.html>
Peter
> Are those eyebars never in compression?
No, they are in tension, only.
If they were intended for compression, then these would have to be much
larger in cross-section, more like an I- or an H-section, in order to
resist buckling and other distorting forces.
But, these members are never intended to resist compression loads, but
tension loads, only, and for a tension member, these members may be
relatively thin, and quite long.
IOW, a high *L/D* ratio.
For a compression member, you must have a much, much lower *L/D* ratio.
Peter
<leansto...@democrat.com> said:
> Yet another person with a reading comprehension problem. I merely
> suggested Gene consult with someone qualified rather than Dr. Bill.
> Why the personal insults?
The Berkeley civil engineering prof on Burns: show -- 7-8 pm -- gave a
very good summary of the safety considerations, without a lot of
hand-waving.
Bottom line finally came out just today from CALTRANS -- the *patch*
was never intended to resist seismic events. Indeed, it was never
intended to resist normally expected wind loads.
The CALTRANS P.E. who *signed* the plans for the *patch* should have
his California Structural Engineer license revoked.
John Higdon
Peter <peter...@rattlebrain.com> wrote:
> Bottom line finally came out just today from CALTRANS -- the *patch*
> was never intended to resist seismic events.
That's not much of a shock. I assumed that it was for that reason it was
being replaced with a whole new bridge segment. I mean that IS what all
this retrofit construction is all about, no?
I hear from the jungle telegraph that the Berkeley guy has sort of a
reputation for being Caltrans-bashing hobbyist. Wasn't he the one who
claimed that the melted overpass (from an accident involving burning
vehicles) that was fixed in record time was all wrong as well?
It was indeed a great hour, but I took it all with a grain of salt.
--
John Higdon
+1 408 ANdrews 6-4400
AT&T-Free At Last
Peter
>> Bottom line finally came out just today from CALTRANS -- the *patch*
>> was never intended to resist seismic events.
>
> That's not much of a shock. I assumed that it was for that reason it was
> being replaced with a whole new bridge segment. I mean that IS what all
> this retrofit construction is all about, no?
You missed the next sentence in my post, John, which was the
significant one, in this specific case ...
*Indeed, it was never intended to resist normally expected wind loads.*
Whether the UC-Berkeley professor of civil engineering is a
*CALTRANS-bashing hobbiest*, or not, he was able to extract the
admission from CALTRANS that the patch was not designed for for wind
resistance.
It wasn:t designed for resistance to seismic events, either, which
means CALTRANS did a doubly bad job.
David Kaye
>The "fix" ... I would term it a "hack" ... was to install two
>identical, or nearly identical, "saddles" at the top and the bottom of
>the cracked/failing "eye bar", and to secure these with tension members.
And these are Caltrans engineers who are supposed to know this kind of thing?
That's scary, given that there are many other similar structures that could
likely fail before the replacement bridge is built.
I saw one of the damaged cars today. It's not a pretty sight. It's a wonder
the folks (visiting from Vancouver I'm told) got out without major injuries or
death.
David Kaye
>That's not much of a shock. I assumed that it was for that reason it was
>being replaced with a whole new bridge segment. I mean that IS what all
>this retrofit construction is all about, no?
But in the meantime a quarter million trips are made across that bridge each
day, and yes, we do get winds in the fall, and yes, we do get quakes around
these parts, and will likely get both before the new bridge is ready to open.
David Kaye
>beyond the normal wear and tear they should receive. You may recall
>the Golden Gate Bridge "celebration" where they shut it down to
>traffic and allowed people to pile onto it, somewhat flattening the
>shape of the bridge. It was after the fact that Caltrans decided to
>check if the bridge was safe under those conditions. Fortunately, much
>like the 747, the GGB has a ton of margin.
I remember that the GGB authority actually asked people to contact them who
may have been under the bridge or nearby at Fort Point who might have seen the
bridge sag. They appeared quite worried that it might fail.
I don't recall that Caltrans had anything to do with the GGB matter, being
that it's not a Caltrans bridge. By the way, some years back (but I don't
remember if it was before or after the celebration, the roadway on the GGB was
replaced by a lighter surface, supposedly 1/3 the weight. Anybody have info
on that?
Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
called ba.transportation -- just so you know.
John Higdon
sfdavi...@yahoo.com (David Kaye) wrote:
> But in the meantime a quarter million trips are made across that bridge each
> day, and yes, we do get winds in the fall, and yes, we do get quakes around
> these parts, and will likely get both before the new bridge is ready to open.
Then I guess we should close the bridge until the new one is complete. I
thought the whole point was that we knew the old bridge was unsafe and
that's why billions are being spent to replace it.
Close it; I don't care.
Peter
> I saw one of the damaged cars today. It's not a pretty sight. It's a wonder
> the folks (visiting from Vancouver I'm told) got out without major injuries or
> death.
That can happen when 5 tons of steel falls down in front of you, and onto you.
No reduncdancy in the design.
Worse, yet, no provision to restrain the tension members, should these fail.
And, a failure in just one of the four tension members would cause the
entire system to fly off the eye-bar, which it did.
CALTRANS now claims that it was always their intention to install such
restraints.
Well, now they get their well-deserved -- NOT! -- chance to install
those restraints.
Still no redundancy in the re-design, however.
Bob Summit
reputation for being Caltrans-bashing hobbyist."
He sounds like a very knowledgeable engineer and one of integrity no
doubt. However the only thing he might achieve is a change in his own
employment status. Engineers live in an absolute world of black and
white solutions. What we have here is the classic tension between
engineers who look for perfect solutions while the managers who make
the decisions have to live in the real world. Caltrans has to balance
the fix for an old bridge with a lifespan of just a few short years
with the impact to the overall economy. Keeping that bridge closed
for days has more than a marginal impact on the Bay Area and even the
entire state. Why would the temporary fix to the temporary S curve
bypass need to be designed to withstand the strongest earthquake or
whatever "Black Swan" like event Mother Nature might throw at it? If
we can't assume some risk, then you might as well shut the entire Bay
Area down and rebuild it from scratch. Of course, somebody screwed up
when they made the eye bar patch. It shouldn't have fallen apart
raining steel onto the upper deck. But the UCB Prof is taking it too
far.
This guy works for Arnold just like Caltrans does, I wouldn't be
surprised to see him move on to an Ivy League or somewhere else. He's
positioned himself as a whistle blower. We need those people but they
don't usually last within the System.
gvk2
> What we have here is the classic tension between
> engineers who look for perfect solutions while the managers who make
> the decisions have to live in the real world. Caltrans has to balance
> the fix for an old bridge with a lifespan of just a few short years
> with the impact to the overall economy.
> If
> we can't assume some risk, then you might as well shut the entire Bay
> Area down and rebuild it from scratch.
The risk ratio on this bridge is not bad at all.
So it fails again, and a few dozen folks are hurt, with perhaps 2
dying. Worth the risk? Yes.
Suppose a sizable quake hit and 150 people are lost as whole section
falls into the bay. Worth the risk over the next couple years? Yes
What the general public is overlooking is that there are tens of
thousands of people residing and working in buildings that are far
more risky and dangerous than is this section of the Bay Bridge.
If such a quake hits, and 100 or even 500 people die on the Bay
Bridge, it will be only a fraction of how many will die in San
Francisco's old office and residential buildings.
Over the next two or three years of risk, the average Bay Bridge
commuter is far more likely to die or be injured in a car crash while
commuting than in some failure of the Bay Bridge.
Thems the facts.......but you don't see them facts on the TV news, so
there and in this news group the "sky is falling" crowd stir up fear
and temporary insanity.
David Kaye
>Then I guess we should close the bridge until the new one is complete. I
>thought the whole point was that we knew the old bridge was unsafe and
>that's why billions are being spent to replace it.
>
>Close it; I don't care.
Well, liike most situations, people eventually adapt. Remember that the Bay
Bridge was closed for an entire month in 1989, and people adjusted. I
happened to like it because I lived on Fell Street, which was then a 3-lane
offramp from the freeway. Without the bridge, nobody took that part of the
freeway and we could actually walk down the sidewalk and not have to worry
about people unable to take the turn plowing into us (as they'd done about
once a month for the year I lived there).
Yesterday I had a customer in Berkeley. Took 35 minutes to get from SF to
Berkeley via the GGB and the Richmond bridge. Took 3 hours to get back.
Almost missed my show last night. However, if the bridge is down for a longer
period I'd just take BART and buses or a ferry boat to my East Bay customers,
or maybe refer them elsewhere or something.
John Higdon
sfdavi...@yahoo.com (David Kaye) wrote:
> Yesterday I had a customer in Berkeley. Took 35 minutes to get from SF to
> Berkeley via the GGB and the Richmond bridge. Took 3 hours to get back.
> Almost missed my show last night. However, if the bridge is down for a
> longer
> period I'd just take BART and buses or a ferry boat to my East Bay customers,
> or maybe refer them elsewhere or something.
I'm a regular BART user. I can't even remember the last time I took the
Bay Bridge. For me, other than packed BART parking lots and long trains
packed with inexperienced riders, it is a non-issue.
Close the sucker!
Peter
>> Close it; I don't care.
Same here.
I live in Santa Cruz County, a transplant from Los Angeles County, and,
although I travel weekly to Santa Clara County for business or
pleasure, I seldom, if ever, travel to San Mateo or San Francisco
counties.
Should I ever venture farther than North San Jose, it would most likely
be via I-880 to I-680, then on to I-80 and ultimately to Nevada.
Phil Kane
wrote:
>But in the meantime a quarter million trips are made across that bridge each
>day, and yes, we do get winds in the fall, and yes, we do get quakes around
>these parts, and will likely get both before the new bridge is ready to open.
Those of us who care know that the new bridge should have been built
and open 15 years ago but for the political posturing of the outside
design "professionals" including the architect who originally
specified five-sided light poles, to show one piece of stupidity.
New light poles can be found in round, square, hexagonal, or octagonal
cross-sections, and no factory was willing to tool up to produce the
relatively small number of 5-sided poles needed for that project.
Couple that to the fact that said architect specified that all lights
be at the same level across the bridge as viewed from the side,
resulting in some which were short enough above the roadway to blind
the drivers and some which were tall enough not to cast any usable
light on the roadway.
And that's only one minor piece of buffoonery. I know this because my
wife's (former) firm had the contract to design the electrical power
and lighting circuits (not to choose the lights) once the final design
was chosen.
Maybe someday I can show the new bridge to my grandson.....
--
Phil Kane
Beaverton, OR
Phil Kane
wrote:
>Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
>called ba.transportation -- just so you know.
I used to read that group but it seemed to not have much technical
discussion but seemed be dominated by weirdos who bickered no end
about Muni management and car-versus-transit issues.
Has it changed?
--
Phil Kane - Beaverton, OR
PNW Beburg MP 28.0 - OE District
Phil Kane
<canta...@gmail.com> wrote:
>He sounds like a very knowledgeable engineer and one of integrity no
>doubt.
Many of the engineers in my "circle", including several UC-Berkeley
graduate PEs in several engineering disciplines, don't feel that way.
The word "nut" arises from time to time.
David Kaye
>Those of us who care know that the new bridge should have been built
>and open 15 years ago but for the political posturing of the outside
>design "professionals" including the architect who originally
>specified five-sided light poles, to show one piece of stupidity.
To say nothing of Jerry Brown wanting a "grand" tower to complement the ones
on the SF side, even though the design was really poor and is more likely to
be fragile to winds and quakes than a design without any tower at all.
>be at the same level across the bridge as viewed from the side,
>resulting in some which were short enough above the roadway to blind
>the drivers and some which were tall enough not to cast any usable
>light on the roadway.
I'm surprised (should I be?) that Caltrans didn't learn a lesson from the
design of the San Mateo bridge, which originally had fluorescent lights
embedded in the center median and driver's eye level. Since fluorescents tend
to be dark at the ends, this resulted in a very annoying strobe effect as
people drove. It was so distracting that I could not drive smoothly while in
the left lane. I'd weave all over. And I'd exit the bridge with a headache.
Then Caltrans added supplemental fill-in lights to cover over the dark areas,
but then that meant more lights to take care of and there were always too many
of them burned out.
Finally, they put in conventional overhead lighting. Took 'em years, though.
David Kaye
>I used to read that group but it seemed to not have much technical
>discussion but seemed be dominated by weirdos who bickered no end
>about Muni management and car-versus-transit issues.
>
>Has it changed?
Oh, it comes and it goes. There isn't the trashing of Muni management nearly
as much as there used to be, and I think people have settled their differences
on car versus transit.
Well, go take a look. The biggest rift is the universal disdain for a guy
named Carl Rogers who posts info about videos he takes of freeways. He calls
it "viatology". That would be fine if his website had anything useful on it,
but the videos are garbage. There are no fights, though, because he's
universally disliked.
Phil Kane
<canta...@gmail.com> wrote:
> Of course, somebody screwed up
>when they made the eye bar patch. It shouldn't have fallen apart
>raining steel onto the upper deck.
Was the "Band-Aid" designed by Caltrans engineers or by outside
contractors? I was under the impression that the in-house engineering
design section of the Bay Area Toll Crossings Division was shut down
decades ago (*) and the function of Caltrans' Engineering Services
Division now is to contract out design and implementation of
engineering tasks. I could be mistaken.
(*) I had a friend who was an engineer there when it closed and he
went over to BART.
Phil Kane
wrote:
>The risk ratio on this bridge is not bad at all.
>So it fails again, and a few dozen folks are hurt, with perhaps 2
>dying. Worth the risk? Yes.
We must live in a different philosophical world. One death is not an
acceptable risk.
"He who saves one life, it is as if he has saved the entire world" .
Eva Cassidy
> On Thu, 29 Oct 2009 09:40:33 GMT, sfdavidka...@yahoo.com (David Kaye)
> wrote:
>
> >Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
> >called ba.transportation -- just so you know.
>
> I used to read that group but it seemed to not have much technical
> discussion but seemed be dominated by weirdos who bickered no end
> about Muni management and car-versus-transit issues.
>
> Has it changed?
> --
>
"Viatologists."
Phil Kane
wrote:
>Suppose a sizable quake hit and 150 people are lost as whole section
>falls into the bay. Worth the risk over the next couple years? Yes
My daughter was heading for the Bridge when it fell in '89. If she
hadn't stopped for gas she would have been on that part of the Bridge
at that time. Don't talk "acceptable risk" to me.
Phil Kane
wrote:
>If such a quake hits, and 100 or even 500 people die on the Bay
>Bridge, it will be only a fraction of how many will die in San
>Francisco's old office and residential buildings.
And that justifies what?
cph...@gmail.com
> On Thu, 29 Oct 2009 09:40:33 GMT, sfdavidka...@yahoo.com (David Kaye)
> wrote:
>
> >Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
> >called ba.transportation -- just so you know.
>
> I used to read that group but it seemed to not have much technical
> discussion but seemed be dominated by weirdos who bickered no end
> about Muni management and car-versus-transit issues.
>
> Has it changed?
I don't think there's much of even that in ba.transportation any more.
Occasionally you
get a good thread, but it's mostly crossposts from a few people in the
highway group
("viatologist", etc.)
cph...@gmail.com
> Phil Kane <Phil.K...@nov.shmovz.ka.pop> wrote:
> >Those of us who care know that the new bridge should have been built
> >and open 15 years ago but for the political posturing of the outside
> >design "professionals" including the architect who originally
> >specified five-sided light poles, to show one piece of stupidity.
>
> To say nothing of Jerry Brown wanting a "grand" tower to complement the ones
> on the SF side, even though the design was really poor and is more likely to
> be fragile to winds and quakes than a design without any tower at all.
>
A few years back there was an article in the LA Times, with a picture
of the proposed Bay Bridge
(a serviceable but utilitarian-looking structure) and comparing it
with a new bridge somewhere
in France...
Not only was the French bridge somewhat nicer looking, but
the picture of the French bridge was real artsy-fartsy, with clouds/
fog blowing
by. The text of the article was annoying, something along the line of
"we oughta be willing to pay more taxes so that we can have a pretty
bridge
just like in France"...
Alan
>I'm surprised (should I be?) that Caltrans didn't learn a lesson from the
>design of the San Mateo bridge, which originally had fluorescent lights
>embedded in the center median and driver's eye level. Since fluorescents tend
>to be dark at the ends, this resulted in a very annoying strobe effect as
>people drove. It was so distracting that I could not drive smoothly while in
>the left lane. I'd weave all over. And I'd exit the bridge with a headache.
I remember those lights. They never bothered me when driving across the bridge,
though it was a bit annoying how many of them were out at any given time.
They made the bridge beautiful from the air at night. I was sorry to see them
go, but the lower power consumption of the new lights made the change "the thing
to do".
Alan
Alan
Your daughter was driving. Thus she follows some principle of acceptable
risk, as accidents can get one killed while driving.
She can avoid the risk of the bridges by driving to 237 and back up the other
side of the bay -- but there may well be more risk due to the extra miles driven.
Alan
leansto...@democrat.com
I stand corrected on Caltrans, but still, that stunt ranks up there
with boneheaded planning at it's worse.
Forum did an hour on the bridge today. I can vouch the first half hour
was pretty interesting, so it's probably worth the download.
Slightly OT, but you may recall the rash of balcony collapses about 15
to 20 years ago. While many were marginal, some were engineered
reasonably well, but the load represented by person was not up to
modern standards. A "man" was considered 150lbs in the day. No
probably finding women that weigh 150 these days.
leansto...@democrat.com
I really don't agree with your "black and white" statement. This kind
of engineering is not digital, but analog. The bridge will flex, and
in fact is designed to flex. Everything is done to acceptable margins
of safety. At some point, you just can't make the margin greater
unless there is a change in technology (materials or design). Just
making the structures bigger gets you to a point where the structure
spends more "time" supporting it's own weight than the load.
Travis James
> On Thu, 29 Oct 2009 09:40:33 GMT, sfdavi...@yahoo.com (David Kaye)
> wrote:
>
>> Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
>> called ba.transportation -- just so you know.
>
> I used to read that group but it seemed to not have much technical
> discussion but seemed be dominated by weirdos who bickered no end
> about Muni management and car-versus-transit issues.
>
> Has it changed?
> --
I've dabbled on ba.broadcast for about a year. It's dominated by a
troll, Carl Rogers and his invented word: viatology. You're missing nothing.
Don Freeman
> On Thu, 29 Oct 2009 09:40:33 GMT, sfdavi...@yahoo.com (David Kaye)
> wrote:
>
>> Oh, by the way, there's a nifty newsgroup to discuss this kind of stuff. It's
>> called ba.transportation -- just so you know.
>
> I used to read that group but it seemed to not have much technical
> discussion but seemed be dominated by weirdos who bickered no end
> about Muni management and car-versus-transit issues.
>
> Has it changed?
Not so much. But hey! We DO have Carl Rodgers. Oh wait... that's not
much of an incentive is it?
--
-Don
Don Freeman
> Phil Kane <Phil...@nov.shmovz.ka.pop> wrote:
>
> I'm surprised (should I be?) that Caltrans didn't learn a lesson from the
> design of the San Mateo bridge, which originally had fluorescent lights
> embedded in the center median and driver's eye level. Since fluorescents tend
> to be dark at the ends, this resulted in a very annoying strobe effect as
> people drove.
Annoying is an understatement. If one didn't suffer from epilepsy at
the beginning of one's crossing, you were still certain to have at least
one minor seizure by the time the bridge was crossed.
--
-Don
John Higdon
Phil Kane <Phil...@nov.shmovz.ka.pop> wrote:
> Many of the engineers in my "circle", including several UC-Berkeley
> graduate PEs in several engineering disciplines, don't feel that way.
> The word "nut" arises from time to time.
Engineers don't run Caltrans; bureaucrats do. In all fairness, they have
considerations that extend beyond the black and white of engineering
disciplines. They have to account for costs to society, public
considerations, and a much more complex risk assessment than even the
engineers do.
Bottom line: there are people other than engineers to blame when
something happens.
Peter
> Bottom line: there are people other than engineers to blame when
> something happens.
But ... the engineer who stamped the plans usually looses his license
to practice, when a catastrophic failure of the instant type occurs.
*The bureaucrats made me eliminate reduncancy, and eliminate
containment of any failed tension members* is not an excuse which will
save that engineer:s license.
John Higdon
Peter <peter...@rattlebrain.com> wrote:
> *The bureaucrats made me eliminate reduncancy, and eliminate
> containment of any failed tension members* is not an excuse which will
> save that engineer:s license.
Actually, I was not implying that the engineers compromise design at the
request of bureaucrats, but rather the decision to use the structure at
all (in spite of risks) belongs usually to bureaucrats.
I can't imagine that we would get much done in a completely risk-free
society (if such a thing can even exist). Every time we step out the
front door, get in the car, ride an elevator, fly in an airplane, or
even ride BART (or be in a BART station for that matter) we take our
lives in our hands.
Peter
> Actually, I was not implying that the engineers compromise design at the
> request of bureaucrats, but rather the decision to use the structure at
> all (in spite of risks) belongs usually to bureaucrats.
Yes, I agree with that point.
When forced to adhere to a rediculously short schedule, one which DID
NOT allow for adequate testing, the "responsible engineer" did what the
schedule allowed for.
On somewhat smaller scale, the instant case of catastrophic failure,
and loss of property, but not loss of life, thank God, is similar to a
NASA "loss of payload" when a launch vehicle does the unexpected.
CALTrans knows what even one hour of down-time is worth, and it is a LOT.
Hundreds of thousands of dollars per day. Perhaps a million dollars per day.
David Kaye
>Actually, I was not implying that the engineers compromise design at the
>request of bureaucrats, but rather the decision to use the structure at
>all (in spite of risks) belongs usually to bureaucrats.
And there is nothing wrong with that. I hate it when some people use the term
bureaucrat in a derogatory way because bureaucrats are necessary to the
function of society.
You're quite correct in the whole cost-benefit analysis thing where X amount
of risk has to be taken as acceptable risk. If only engineers were in the
loop making decisions on designs, nothing would ever get done because
engineers want a 0% risk, something that boosts the cost of a project up
toward infinity.
leansto...@democrat.com
I don't know about 0% risk. You design to accepted standards.
I noticed Caltrans must read my posts since they have decided to
installed electronic monitoring devices on the bridge. ;-) Well,
perhaps they thought of adding sensors without my help.
VanMan
hour.
Some good discussion between them, and a few good calls.
I'm glad I'm many miles from the Bay Bridge!
Ciccio
Was it Prof. Astaneh?
Ciccio
Peter
>> I'm glad I'm many miles from the Bay Bridge!
>
> Was it Prof. Astaneh?
Yes, it was.
The prof stated that the combined area of the four tension members in
the CALTrans "patch" is significantly smaller than the area of the
eyebar which has a cracked eye, and he described the preferred eyebar
repair method, which is significantly different than CALTrans' "patch".
(The Silver Bridge, which failed catastrophically from an eyebar
failure killing more than 40 persons, one of whom has never been
recovered, had only a 1/4" crack in its eyebar, yet the crack in the
Bay Bridge's eyebar is 2".) The prof referred to the Silver Bridge
failure, and stated that the failure mode in the Bay Bridge would be
the same.
Structural members of the type in the Bay Bridge's cantilever span
section are known as "fracture critical" as the failure of a member,
such as the eyebar in the instant case, would result in the entire
structure failing.
CALTrans' claim that the eyebars are in multiples in order to provide
reduncancy, and, therefore, that the Bay Bridge's cantilever span
section is redundant, was refuted by the prof. The prof stated that the
loads are distributed across all members.
The prof stated he has all the drawings for the Bay Bridge, obtained
when he worked on the Loma Prieta Earthquake retrofit of the bridge.
The prof stated he offered CALTrans assistance in the instant case, but
his offer of service was refused by CALTrans.
Phil Kane
wrote:
> If only engineers were in the
>loop making decisions on designs, nothing would ever get done because
>engineers want a 0% risk, something that boosts the cost of a project up
>toward infinity.
Engineers want 0% bull***t. We're fighting this point with one of our
clients at present. It's not easy.
Phil Kane
wrote:
>The prof stated he offered CALTrans assistance in the instant case, but
>his offer of service was refused by CALTrans.
Guess why......
bozo
<leanstothel...@democrat.com> wrote:
> On Oct 29, 11:41 am, Bob Summit <cantara...@gmail.com> wrote:
>
Remind you of anything? Person? Place? Institution? Broadcaster? Radio
Station?
-bdn-
Ciccio
> On 2009-11-01 01:58:16 -0700, Ciccio <frances...@comcast.net> said:
>
> >> I'm glad I'm many miles from the Bay Bridge!
>
> > Was it Prof. Astaneh?
>
> Yes, it was.
>
> The prof stated
[Good summary snipped].
I heard him on Barbara Simpson's show on Sat, where essentially he
said the same.
Ciccio
leansto...@democrat.com
I thought the Mothman took down the Silver Bridge?
cph...@gmail.com
> A few years back there was an article in the LA Times, with a picture
> of the proposed BayBridge
> (a serviceable but utilitarian-looking structure) and comparing it
> with a newbridgesomewhere
> in France...
>
> Not only was theFrenchbridgesomewhat nicer looking, but
> the picture of theFrenchbridgewas real artsy-fartsy, with clouds/
> fog blowing
> by. The text of the article was annoying, something along the line of
> "we oughta be willing to pay more taxes so that we can have a prettybridge
> just like in France"...
Peter
Looks like CALTrans is looking at yet another closure of the bridge.
The abstract description, reading between the CALTrans announcement's
lines, is to apply a formal eyebar repair, of the very type which
Astaneh described as the preferred repair method during his phone
interview with W.