Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
Still no pictures that would show the status of potentially shifting slabs on the spill way.
Still no pictures that could be used to assess how much erosion occurred in the last release.
Still no word on how much more debris washed into the river at the base of the spillway.
All of the above information exists and should be freely available.
There is only one possible conclusion: It is being deliberately withheld.
How many core holes will they drill? DWR is not revealing information via gallery photos at the moment.
Larger drilling rig reveals that DWR is coring holes in the main spillway to sample the rock quality & depth below. Larger vehicles also observable in this activity. Note that DWR has not provided any images of this activity on their gallery (as of yet).
Up to Four Core drilling rigs are in operation on the main spillway since April 3. Images were captured from far views of the DWR drone video. Still no close ups of the coring rigs (drone or from DWR gallery pictures). There are a distribution of white plastic boxes on the spillway. Not sure if these are for storing the core samples, but the distribution of these boxes gives an indication of all of the areas intended to be cored/drilled. (see the prior post image).
Larger drill rigs - likely coring holes to sample the subsurface rock quality and depth.
Image capture reveals up to 4 drilling/coring rigs are in use.
Juan Browne, who is doing the youtube updates on the dam, commented in a report some time back that DWR's drone video has missing footage due to DWR editing (in certain areas). IIRC Essentially, Juan was inferring/commenting that these edited zones were "not desired by DWR" to be available.
Well, good,
It looks like the shot-crete wall at the end of the broken spillway
has held up much better than I thought it would.
There is a little bit of washing-out or undermining over there at the left side.
Thanks for the images and links - yes, the shotcrete held up well at the end of the spillway. That’s good. Depending on the plan, it may have to last a while.
It looks like they’re trying to do it right this time. i think that there was a sudden sobering concept that the dam is really important, and not just to 200,000 people that probably didn’t vote for Moonbeam, but to all of California.
Regarding the washing out - I think tehy might have been experimenting with the downward ramp of shotcrete (or, they were using up what was on the truck). I’d like to have seen them build a ramp all the way down to the gray rock so that the spillway can be throttled back a bit if desired.
I’m not sure, though, how it would hold up to having a constant waterfall striking it. I suspect that something like that would need to be designed and built with some strength if it was going to last more than a few days.
A video from the dam, March 3rd, I believe. I’m guessing that it was edited to remove “critical infrastructure” information...
https://www.youtube.com/watch?v=6d-_NZsUoEc
FYI, in the March 4 video by Juan Brown, he seemed to kind of poo-poo the idea of some kind of conspiracy to hide info and seemed to diss the Sacramento Bee for making it look there’s a cover-up.
https://www.youtube.com/watch?v=Mi9auu7muZY
I suspect that somewhere between what he says and what they say lies the truth. It’s easy to discern that they have something to hide beyond the “critical infrastructure”, given the years of issues that have been appearing since this event began. Time will tell if they’re being less than honest and hiding behind the designation or not.
I like what Juan’s been doing so far, so I’ll give him the benefit of the doubt here for now.
Chico-ER also has noted a history of other issues where they cannot get straight answers.
DWR again proved to be "politics first" in their answer to a photograph showing the initial cavitation damage at a seam spall at the blowout failure.
In watching a long interview with the editor describing all of these incidents & seeing the DWR responses in the news, there is a true history of distrust with DWR.
First and foremost, the Engineering responsibilities on the Dam is in a space where there are no excuses. There must be demonstrated responsibility, accountability, and honesty. I noticed a "change" when the FERC recommended experts entered the equation. The first public "correction" occurred directly from the BOC experts engineering statement(s) that blew up DWR's position/statement on a key engineering point.
Being in failure analysis for 30 years as a consultant/engineer/scientist to go in and fix the problems at major corporations that the top scientists/engineers couldn't, you immediately recognize any "politics" at play as the truth of science/engineering/physics you cannot hide. In trying it eventually reveals any culture of incompetency, poor engineering judgement, or outright machiavellian intent.
I've seen the "cut" editing points in the DWR drone videos, I know what I'm looking for. You can figure out what they don't want to be seen.
To me, the warnings of Stagnation Pressure Failures were in the dam specialist expert community with papers & magazines publishing this information including expert tools to analyze if a spillway is at risk of exploding (water penetration, volume, surface area, cracks, seams, flow rate, anchor strength, etc). Yet DWR had the audacity to say (paraphrasing) "when we find out the failure cause we will let the rest of the world know so they could benefit from our findings". Horse puckey. They know right now (cause). For them to imply that this is something all of the dam experts in the world haven't run across is delusional.
The timing of them filing the CEII precisely 2 days before the next damaging BOC report was to be made public defies probabilistic odds. If they were told to do this inspection by the experts, why isn't this data in the expert's report? (the 4.26MB vs 1/2kB file sizes reveal that the BOC report does not contain a fraction of the CEII filing report).
Water is escaping the upper chute so badly that it is saturating the hillsides - that is why the BOC was stunned in saying "this should be investigated" when waterflow continued out of the drains after the gates were closed. The only answer is that there is a saturated "basin" in the chute hillsides - reflowing back to the lowest point (drains). Water is going everywhere.
No, I firmly believe DWR does not want all of the dirty laundry exposed. The only hope is that they are now under scrutiny by FERC through the board of consultants. However, the lives of the public below the dam are not getting the truth. This is unconscionable.
#OrovilleSpillway Incident press briefing tomorrow at 2 p.m. Watch via DWR Facebook live. http://www.facebook.com/CADWR
https://twitter.com/CA_DWR/status/849758564763566081
"OrovilleMR: Editorial: Too many dam questions, not enough answers"
OrovilleMR: Editorial: Too many dam questions, not enough answers
(Snip)
"State legislators aren’t getting answers about the Lake Oroville spillway. Neither is the federal government. Or the county government. Or journalists. Or interested citizens."
"It’s all coming to a head as two north state legislators whose districts include Lake Oroville are demanding answers."
"Well it’s about time."
.
"Then, the next day, the Sacramento Bee reported DWR wouldn’t release documents from an independent panel of experts that the newspaper said “could shed light on repair plans and safety issues at crippled Oroville Dam.”
"A DWR spokeswoman cited security concerns and declined interview requests on behalf of agency officials."
.
"Any attempt to withhold reports or documents of this nature will be viewed by our constituents as an attempt to cover up the truth. And that simply will not be tolerated,” they said. “This lack of transparency only elevates the concern. This emphasizes the need for legislative oversight hearings.”
.
I’m not an expert on dams, but I do have a fairly good overall technical background. I appreciate the level of detail and analysis you and others on this thread have provided.
It’s clear the DWR/politicians have done a terrible job taking care of this dam (not just the spillway), and they are covering that up.
It’s also clear they don’t want us to know the current status of the main spillway. If it was good they’d be bragging about it.
This is not just an academic issue. The potential downside here makes New Orleans look like a picnic.
From what I read on another board, a low end estimate of the snow pack coupled with the assumption of no further rain would still require 50 days of spillway operation at 40K fps in order to drain the inflow from spring run off.
That estimate is way low. In reality, the snow pack is close to double the “normal” level, and more rain is coming. When the spring melt starts it won’t be a nicely spread out flow either.
In other words, it won’t be a “normal” year for the spring melt. Double the “normal” sounds more likely, and the inflow will have peaks and valleys.
So... How high will they actually have to crank up the spillway at the peak, and for how long? Can the spillway (and the dam, if the spillway goes) hold up to that?
I’m glad I don’t live downstream of this dam.
DWR's Critical Energy Infrastructure Information status was initiated by a "follow up" of Anchor Tendon inspections AFTER the tendons were tested in 2016 with "satisfactory" findings. The Anchor Tendons were tested in 2016 using a reflective dispersal wave technique. The findings were "satisfactory" (i.e. no issues with the testing). (the 2016 report did state that other "Follow up research and results are expected within 12 months"). Yes, finding some "corrosion" in these bars will degrade the structural strength of the design, but rating them as CEII "Secret" regarding as an issue by an "attack" requires someone looking out for a person with a large wrench.
The CEII rating does not make any sense at this point in time.
Note: Anchor Tendons in the main spillway gate structure are used to strengthen the concrete using "tension bars". These end-threaded steel bars are anchored in the concrete at one end, tightened using a nut upon a "bearing plate" at the other end, and then grouted in the sleeve within the concrete. This technique is called Bonded post-tensioning. Rows of Anchor Tendons provide tensile strength to the concrete where the Trunnion anchor & pivot plate are mounted and facilitate the radial gates rotation & load forces. 24 Anchor Tendons are emplaced for each Trunnion pivot plate - yielding 48 Anchor Tendons total per Radial Gate.
So why now? The Anchor Tendons tested "satisfactory" in 2016 and approval was given. Now there are "issues" with the Anchor Tendons that risk "attack" (security context). The only way to get to the Anchor Tendons is by loosening the nut. But there are 48 Anchor Tendons per each Radial Gate - thus 48 nuts. Technically, this ability to loosen these nuts existed from the origin of the construction of the spillway. To get to these, a person would have to know where to climb to get access. They are not "just by the roadside of the spillway bridge".
The more significant issue is that DWR has revealed that they found "structural information" with the integrity of the Anchor Tendons (such as - the ultimate enemy - corrosion). The fact that they state that Gates Nos. 3, 4, 5, 6, & 7 are noted in the "Structural Inspection" infers that this integrity problem could involve up to 240 Anchor Tendons. To what extent have they found corrosion? To what degree has the strength of the design been reduced? Is there a safety margin at 100,000 cfs? Is there a safety margin at 50,000 cfs? Where is the safety margin (forces)? Keep in mind that these steel tension bars are rated to max 160,000 psi each (tensile).
2016 Inspection report: Radial Gate Anchor Tendon Testing performed using Dispersal Wave Technique. Follow-up to be done within 12 months. 2016 report findings were "satisfactory".
2017 March 22 DWR letter to FERC - Requesting CEII status - Cover Letter Identifies "Structural Inspection of Radial Gate Follow-up" (i.e. Follow-up to 2016 Radial Gate Anchor Tendon Inspection report) NOTES 5 GATES in this CEII request letter..
2016 Inspection report Image 20 - showing Anchor Tendon bolts, nuts, & bearing plates - protected with plastic covers, and grease at the tips (& plastic caps) to shield from moisture - corrosion protective measures.
2015 Inspection report Radial Gate image 11: "Nothing new or unusual was observed at any of the tendon anchor locations." - 2015 report findings were "satisfactory".
2015 & 2016 found "hoist deck" AND spillway bridge "satisfactory" (note: hoist = motorized cable units that individually lift each of the radial gates).
Thank you for finding and posting this. There have been rumors in the water community for about four weeks that there was an issue with the spillway gates at the dam. They seem to have started in earnest about the time that they could not get some of the gates to seal when closed. Remember the angle sandbag “berm”. Apparently there has been divers working on the gates to seal them when closed- unconfirmed by myself.
All of the system’s weaknesses and lack of proper maintenance are coming to light. NWS is forecasting a hugh AR starting late Thursday.
(More Info)
(1) There are built in safety margins in the structural loads of the design. There are also a large number of tendons per radial gate. (i.e. this does not rise to the level of the definition of what CEII is intended for - only being used as a "scenario" technicality).
(2) Three hundred and eighty four individual tests would have to have been performed in Time Domain Reflectometry type of 3D analysis of the steel rods, data analyzed, calculations performed, and then reports generated just in time for filing 2 days before the next BOC report was to be released....Awful quick to get this done "just in time" to get a CEII status.
This maneuver looks just as what some may believe... A maneuver to affect information release. The irony is that it also "bottles up" critical new radial gate structural information release regarding the spillway operational integrity concerns which the public shares - (i.e. to what level is the spillway damaged in its safety margins).
I've noticed that FReepers use "hugh". Is this related to a meme on the Zepplin disaster where passionate reporter says "oh the humanity"? - that this morphed into "the hugh manatee" here? ... or was it a typo....
= =
There could be a number of factors regarding leaking. There was a tremendous amount of floating & partially floating wood debris that could get trapped as the gate is lowered. Keep in mind that the side seals are hydraulically inflated rubber seams that are activated after the gate bottoms out. They have stainless steel slides on the concrete for the teflon edge coated inflatable rubber seam to compress against. Any trapped debris will compromise this inflation.
IF there was an issue with the tendon anchors, such that the gates were shifted, there would be cracks or "pull apart seams" observable at the Trunnion beams at the concrete columns. For this to happen, a group of tendon anchors would have to have drastically failed (i.e. snapped, sheared).
I would tend to believe that a Project Safety Compliance Report Cover Letter would not have referred to a "Follow-up", (i.e. Follow up to the 2016 anchor tendon testing), if there were failed anchor tendons on 5 gates - such that trunnion beams have moved.... but rather alarms going off that the spillway is in a very dire failure condition (should not be operated).
I was pondering what the ramifications of debris not clearing the gate seal area when the gates are closing. Seems to me with the flow and associated pressure that some could possibly lodge in a critical location. It also seems that if a gate doesn't seal the first time that one could just cycle it again and see if the material dislodges.
I have no information that the tendon anchors have or are the root of a problem, however it would not surprise me. Critical member(s) in a critical place.
Contrary to what most people think Teflon degrades over time and the Teflon slides could be damaged from operation after degrading due to exposure to the elements. The seals could also be degraded with time. Man made materials always fail after prolonged exposure to the elements - just a question of how much time. If you want to be wildly rich invent a coating that doesn't fail in sunlight, that is economical and easily applied on a structure.
Posted earlier - maybe worth repeating...
"It is interesting that common law assigns "strict liability" to certain "abnormally dangerous" undertakings. Damming up water is one such "abnormally dangerous" undertaking. "Strict liability" means that negligence is not required for liability if damage occurs from the undertaking. One is liable simply by taking on such an abnormally dangerous activity regardless of how careful he is.
"But this is government, so who is strictly liable? The government? If so, how does government pay for the damages? With their money? But government doesn't have any money. It only has OUR money. So government pays for damages with the money of those it damaged. So effectively, government isn't liable for anything.
One way of looking at this government conundrum is that because building the dam was an activity by a representative government, it means that at least theoretically that the dam was actually authorized by the collective people who wittingly or unwittingly have taken on that liability themselves.
"Anyway, in this case, it looks like the people need to kick some butt to get corrective action to move this thing away from what [could be] an imminent threat [or at least a very costly one] on a massive scale."
the lives of the public below the dam are not getting the truth. This is unconscionable.
From what I've see, when it comes to choosing between threat to lives and property versus political futures, the government always chooses the latter and it applies the word "unconscionable" to citizens, never to itself.
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