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  1. Stutz

    Stutz New Member

  2. timearp

    timearp New Member

    I have to agree! I've been lurking for a while on this forum and whilst consolidated, nothing new was mentioned that hasn't already been posted here. Thanks to the contributors to the forum, it's made for very interesting reading.
     
  3. aczlan

    aczlan Member

    One that stuck out like a sore thumb was page 18/11 (18 of the PDF, page numbered 11) which had the following picture:
    annotated.JPG
    That appears that he took sweepleader's picture and added two text boxes:
    Is there another version of that document that has sources listed? If not, it might be interesting to see what UC Berkley's position on plagiarism by their professors is...

    There are a couple of things that I hadn't seen (like the lower left (when looking up the spillway) slab rotating downhill and the left edge separating at the wall) but most of it has been hashed out on here.

    Aaron Z
     
    • Agree Agree x 3
  4. Jeff Semenak

    Jeff Semenak New Member

    Apparently, the Professor has rather sloppy attribution skills. It would have been awesome to see a footnote crediting the picture above to sweepleader.
     
  5. AlmostaCE

    AlmostaCE New Member

    Well, in truth, the image is a crop from a DWR photo, only the colored lines are the work of SweepLeader, but I read the entire report and kept seeing all these photos and concepts that had been built here through our discussions.

    I was humored - seems we at least have a professional who agrees with our armchair work.

    Brad
     
    • Agree Agree x 1
  6. whoosh

    whoosh Member

    I too have been tracking the spillway here since very early on, and agree that part of the referenced document are familiar. One image however which I do not recall from here (doesn't mean it isn't here) is this one.

    upload_2017-4-19_9-10-54.
    indicating structural layers and the probability of water beneath the slab.

    But overall, I think we've always known that this spillway construction experienced a lot both cut and fill, and that the "bedrock" was not homogeneous. Yet, what else is to be expected in the mountains? It's an imperfect scenario which was likely exacerbated by the recent extreme moisture swings.

    Maybe they should remove most of the spillway and let a few heavy spills continue to "powerwash" the subsurface before proceeding. :)
     
    • Like Like x 1
    • Agree Agree x 1
  7. sweepleader

    sweepleader Member

    This one stuck out for me too, but it is really wrorke's work on a cropped DWR photo that I started with. And it was AlmostaCE's comments that caused me to illustrate this version of the drains. There, now it is all atributed properly, maybe.

    Should have been credited to Metabunk.org in my opinion.
     
    • Agree Agree x 2
  8. aczlan

    aczlan Member

    True, the original photo is from the DWR, but the additional lines should have been credited to sweepleader/Metabunk or he should have redone them with his own lines (I am fairly certain some of the other annotated pictures also came from here, but that one stuck out like a sore thumb).

    Aaron Z
     
  9. aczlan

    aczlan Member

    I emailed the Center for Catastrophic Risk Management at UC Berkeley about this and got the following response (quoted verbatim from the email I received):


    Aaron Z
     
    • Like Like x 3
  10. sweepleader

    sweepleader Member

    Yeah, I guess "Metabunk.org" is pretty hard to spell, eh? Much harder than DWR. :{)
     
    • Like Like x 2
  11. Boilermaker

    Boilermaker Member

    Professor Bea's report has been picked up by other print media such as the Sacramento Bee and in interviews he's added a bit to his comments in such text as there is in the report:

    http://www.mercurynews.com/2017/04/...ay-emergency-developed-and-propagated-by-dwr/

    By "inspection documents" I take him to mean the records of DWR's own inspections and repair decisions rather than the annual regulatory reports that are in the public domain and listed in the report.

    It will be interesting to see if the Oroville independent forensic team come up with anything different or whether they endorse any significant part of the "excuse list."

    (Also Juan Browne has done a video largely on the report - I don't link it here as it really only repeats what the report says.)
     
  12. bRad

    bRad New Member

    I for one wanted to note how lucky Oroville, DWR and everyone else was that they had Director Coyle on board that disastrous night. When the water started over the emergency spillway and the erosion was apparent immediately. It would have been massively stressful. Calling for the evacuation of town at the same time. Then someone has to throw out the idea, "we need to reopen the main spillway".

    It is clear now, in hindsight, when they reopened the main spillway they saved that structure and that town. I am sure in the heat of that moment, that was not so clear. They kept level heads, and managed with what data they had in hand. There was certainly a bit of luck that the remaining spillway structure and enough solid rock to handle the flows.

    Every decision the response team has made sense, seems from what is available, to have been great decisions. Closing the Hyatt at the right times. Pushing massive debris removals. Anchoring and shotcrete on the remaining spillway. Armoring the emergency spillway. All seem, in hindsight, to have been done in the right order at the right times, to create more options as they went along.

    I take a slight exception with the AP article's headline
    (link for reference: below). I do not think there was much wrong in the 'handling' of the crisis. I realize this is like editors/authors trying to come up with a sensationalized headline. Just feel it does not quite convey the correct sense.

    Sure there was a lot wrong with the operations and maintenance of the structure that led to the crisis. That has been well documented, discussed here. The overall handling of the crises once the hole appeared in the deck, seems pretty good.

    ref:
    https://apnews.com/0a4b46c359444c58918ad374f7cd3d28
     
  13. MortarBoarder

    MortarBoarder Member

    OK, so he thinks there was erosion under the slabs, and the massive failure was due to slabs being lifted (and destroyed) by the water flow. Will be interesting to compare to whatever the official report decides.
     
    • Like Like x 1
  14. Boilermaker

    Boilermaker Member

    He says something more than that, including that cracking of the spillway deck over the drain system shows that there was inadequate depth of concrete used, that the main deck fracture is directly on the line of one such drain and that the wrong standards were used in regulators' periodic assessments of the spillway's condition. In any case, DWR has now been drawn into giving a partial response to Prof. Bea, which is reported here:
    http://www.krcrtv.com/news/dwr-resp...ay-construction-maintenance-defects/454495503

    Maybe the only item of interest in this is that the DWR spokesperson repeats the comment made by Mr Croyle two press briefings ago that there was a lot more concrete used than the original construction specs refer to. She said that this was in the area of the spillway "core" without saying (or being asked) where that is. I've taken this to refer to backfill on the rock surface under the deck but if so a lot of it must have got washed away.
     
  15. jpal

    jpal New Member

    There appears to be a consensus developing that the initial blowout was preceded by the closest drain being clogged. Bea suggests that this may have been due to tree roots invading the drain, and sites DWR reports that were concerned with tree growth adjacent to this drain. Bia also provides evidence in the initial construction photos that there may have been a natural source of groundwater in that approximate location, which might attract tree growth.

    Bia suggests that the drain clogged from the tree root built up enough hydraulic pressure to lift the slab and cause the initial blowout. This appears plausible, as only a psi or so across the slab would be sufficient.

    An alternate plausible explanation is that the water pressure followed the path of least resistance up the tree root and out the side backfill. This might explain why the side backfill appears to wash out before a breach in the spillway slab is evident.

    Whether the clogged drain pressure pushed the slab up or scoured the subbase out, if it was a tree root which at least partially induced the initial failure, and this was a potential which was known and acknowledged by DWR in advance, then this indicates that this particular mode of failure was quite preventable.
     
  16. SeanT

    SeanT Member

    DWR plans to start blasting, this is from a few days ago and I haven't heard any blasting yet (I'm 1.5 miles from the spillway), I'm assuming they'll wait until they can stop outflows from the main spillway.



    From http://www.water.ca.gov/news/newsreleases/2017/042017_oroville_construction.pdf