Need a book? Engineering books recommendations...

Return to index: [Subject] [Thread] [Date] [Author]

Bay Bridge related info from Astaneh

[Subject Prev][Subject Next][Thread Prev][Thread Next]
Dear Friend:
If you are not interested in Bay bridge or my work on it, please discontinue reading this e-mail, press the Delete button and move on.

 If you are interested, here is just one of the e-mails tat I got from one you and my response in case you are interested.

As always, best wishes to all.
Hassan
==============================================================================
Dear (name redacted): Sorry that I missed your e-mail and did not respond promptly. Here are my answers inside [Brackets].
Thank you so much for taking the time to comment. Without friends like you I would be rudderless!
Take care. Hassan


.At 08:47 AM 2/15/2005 -0800, you wrote:
Hassan,

Thank you for including me as part of the group.  I learned much from your website and proposal (primarily about the existing design).  I do have some comments on your efforts: 

[Hassan: Well, I have learned so much fromyou guys out there in trenches as well. So, we are even!]

I think the proposal has some significant merit, especially in terms of getting the anchorage to be "traditional".  I would imagine that the largest challenge with your proposal is the eastern anchorage.  A major anchorage in the bay mud at the depth we are talking about present challenges in terms of construction (and possibly capacity).  In addition to the engineering and construction challenges, the environmental impact will be a big deal and could necessitate another EIR - possibly crippling the progress of the project (based on my understanding of the way EIRs work).


 [ Hassan:There is NO bay mud below 20-30 feet below water. That is well established by many bore holes and sound wave testing one by our seismologist at UC , working for my Bay Bridge project and one recently by Caltrans. Caltrans , unfortunately for the people, has drummed up this scare that the Eastern Spans are sitting on mud to get the Self-Anchored bridge approved. Instead of retrofitting the existing bridge for about $400-$500 in todays dollars, which could be done and finished by 1996,  the management of Caltrans and some members of its advisory board have created a $200 million dollar consulting project for themselves and their own firms and a $6 billion dollar "crooked" bridge for us that cannot withstand a relatively small car bomb.]

[Hassan:The environmental challenge is another trick by the same people who are showing this self-anchored bridge in our throats in day light. ] The only environmental issue regarding the placement of anchors in the Bay Waters is to just ask "Mud Sharks" which are now very few in the Bay just to move over!]


.

Unfortunately I can't speak to the construction aspects, but I would guess that there are more significant challenges associated with the anchorages for this bridge as indicated in your proposal compared to the anchorages for the Carquinez bridge.
[ Hassan:The East anchorages are just about twice the size of regular piers of the viaduct under construction.. No big deal. The west anchorages on the YBI are just two cone shaped wells with finger eye-bars that are atatched to cables placed in these wells and the wells are filled with concrete. Those brilliant engineers who came with this idea have done it for the west West suspension spans this way in 1935!]



One question - does placing the main anchorage close to the water present vulnerability to a higher percentage risk (ship damage, boat bombs) with more plausible catastrophic results? 
[ In my opinion, cales are the most resistant elements to blast that there is unles you are like that very naiive terrorist who was planning to cut them using flares!. It would have taken perhaps months to do it for him. If he only had taken a steel design course, he wouldn't have bothered. You need to protectcables from terrorists diectly placing large amount of high yield explosives on them. ]



 
Based on your paper, I'm not sure what is the best solution to the "flaws" you indicate, but it appears that SAS is NOT the solution.  A skyway is a solid answer to the budget, construction and vulnerability problem, all in a single design.  If I were on a peer review panel at this point - I'd vote for the skyway (for technical reasons as well as constructability concerns).  I hope my comments are helpful, take care.



[ Well, the problem with those who want to sell this self-anchored bridge to us is that they have been masters of disingeneous statements. They show the skyway with nice compter graphics and only just the above-water portion of it. So you do not know what is under water. By the way I think the right name for it is "viaduct" and not skyway. Naming it skyway, which I have not seen in the bridge literature, is another way of supporters of these concrete boxes on stilt ( as Mayor Harris of Oakland pu it years ago) to us with a  pleasant name.  Now, if you show the under water soil profile, near YBI, there is a big ditch to the east of the Island which currently the cantilever truss spans over it. Apparently this ditch was dredged in 1930's and 40's to make it suitable for the ships and submarines, but it was a natural ditch. According to geologists, before the last ice age ended, more than 20,00 years ago, the Bay was actually a valley and was not filled with water yet. There was a river there,  part of it still in Berkeley and called Tamascal (sp?) creek. The river passing to the east of the YBI rock has made the ditch there. The designers of the Bay Bridge in 1930's, which included Leon Moisieff  (sp?) and  Dean Derlett of UCB, were aware of this deep ditch and crossed over it using Cantilever truss and let it be a ship crossing. Now after 60 years, it seems, people who recomemnded this solution to the Governor, never looked below the water to see that you cannot reasonably put piers in the middle of it which this viaduct option requires two of them. The depth of water there is more than 100-150 feet and adding to it 40-50 feet of mud accumulated over the years at the bottom of the ditvh and the height of the piers above  water (240 feet) you will need a pier about 500 feet tall, just a foot taller than Embarcadero 4's 499 feet height!.  Knowing you, I am sure, if you were on the review panel, before you recommended viaduct ( and not the skyway!) you would ask for a soil profile and that would be the end of it!   
Sorry for the length of this e-mail, but I tried to pay you back for your time in commenting with an interest]
 

Abolhassan Astaneh-Asl, Ph.D., P.E., Professor
Web: www.ce.berkeley.edu/~astaneh
Department of Civil and Env. Engineering
781 Davis Hall, University of California, Berkeley, CA 94720-1710, USA
Campus Phone: (510) 642-4528, Home Office: (925) 946-0903,