Emergency: California’s Oroville Dam Spillway Near Failure, Evacuations Ordered

Breitbart ^ | Feb 12, 2017 | Joel B. Pollak1

[Ray76]

We’ll have to come up with a name for the gulch running down from the ES.

Maybe Close Call Gulch or Rotten Rock Rapids or Lucky Gulch....

[EarthResearcher333]

New Access Routes - Oregon Gulch Bridge side - Protects Weak Capacity Spillway Bridge

Large Pipes for Oregon Gulch Bridge reveal plans of new access route(s) for emergency construction of the Spillways. A west approach on the north side of the Feather river optimizes access to the three main focus areas of construction. The Lower Main spillway + plunge pool, the Upper Main spillway, and the Emergency Spillway. This access side will also be where the large dredge pilings of material reside. Portland Cement mix & other supplies could travel in volume from the new access side without threatening the critically sensitive spillway bridge. The current use of the spillway bridge, by heavy construction trucks, are limited to near 5mph an only one vehicle at a time. It would be a wise choice to eliminate the wear & tear in flexure loads on this critical bridge. Any failure of this bridge would threaten the structural integrity of the Radial Gate headworks.

The new access routes likely will require addressing an issue of dust of which residents of Oregon Gulch Road have been complaining about. That is, if that road is chosen as a main access route. The other option is upgrading the road on the north side of the Feather River. That road may take a bit more work to upgrade than the upper route. It's possible that both routes will be used to facilitate alternate travel & coordinated staging arrival. I wonder if DWR has notified residents of what they may be in for…

The Old (existing) access routes on the southern side of the Feather River would facilitate access to the south side of the upper main spillway, such as large cranes for Upper Spillway work. Having two "sides" for strategic equipment allows for less congestion. One example: Prefabrication of on-site items may be done on the south side with cranes lifting these items in place in the Upper Spillway chute work area.

ES bridge 1 and ES bridge 2 are the critical dependencies. Will they leave these as "fill" bridges? If so, a "shut down" of the main spillway would force the emergency spillway to activate if snowmelt outpaces the Hyatt power plant outflow. This would damage or destroy the "fill" bridges - only to be quickly re-filled if the emergency spill doesn't escalate in size and create more disruption.

These plans strictly depend on the cooperation of nature.

[abb]

Just thinking out loud here. Perhaps some of the heavier equipment and the cement could be barged in.

[mad_as_he$$]

I don't think the river is navigable down from the dam. I have been there a few times and never seen anything but small pleasure boats. Close by rail would be the most likely. The UP track follows the river pretty closely and goes all the way to the head waters.

[jpal]

To EarthResearcher333:

Thanks again for the post cross referencing your radial gate anchor tendon diagrams and putting them together in one place. These really help in gaining a better understanding the scope and scale of the issues; but do generate fodder for further questions! I’m still way down on the learning curve, but trying to catch up.

Replacing the gate anchor tendons appears to be quite a significant endeavor, as you’ve been pointing out for a while now. Besides the problems you identified in accessing the internal “Tees” from the side of the columns, and spreading the grout out enough to eliminate air voids on both sides of the sleeve, I would think there might also be difficulties with the coring out of these 37’ long tendons in the first place. The bit would have to drill through a composite of steel, grout, concrete, and rust for 37’ consistently without clogging enough to bind or break. If the grout and rust hold the tendon in tension, the compressive force reaction would substantially increase the bit’s tendency to bind. A broken or non-recoverable bit could result in a tendon that couldn’t be replaced, so there would be little room for error across the thousands of feet of coring required.

Is it a common practice to core out and replace tendons this long? How long does this take per tendon? Does the hole size increase significantly? Do you have pictures showing how this is actually done for tendons of this size?

Are there other plausible alternates for restoring the full original design safety-factor gate tension? Assuming they could find the room, could they drill new holes and grout in additional new tendons to compensate for the strength loss from the existing corroded tendons? This might strengthen the gates sufficiently until proper diagnostics could determine which of the hundreds of tendons actually need replacing, as that may not be until later this year, on DWR’s schedule. I would think DWR would need a “Plan B”, if they don’t have time to replace the tendons this year, which seems likely.

[abb]

Do you know if the contractor has moved in a rock crusher/classifier and begun processing the aggregate on site?

[KC Burke]

Let’s talk about who I understand was the pick to do the repair contract.

Kewitt has their act together. This is their type of work. If I was a Program Manager for DWR this would be my first pick.

They are one of the top ten and they do jobs like this all the time.

[abb]

https://en.wikipedia.org/wiki/Kiewit_Corporation

[EarthResearcher333]

"Do you know if the contractor has moved in a rock crusher/classifier and begun processing the aggregate on site?"

There is an onsite rock crushing plant already in operation. Haven't been able to locate it with images, yet. (I've looked in the areas of the large stockpile of material removed from the diversion pool - nothing stands out). DWR reveals that this current rock crushing unit "provides gravel and rocks to be used for paving and recovery efforts at the Lake Oroville spillway site". Notice the inclusion of the words "paving" and "recovery efforts". These are clues to the next steps. Image was taken April 21, 2017. I suspect they are going to move quickly on building the access roads. Tidbits of info come out from press conferences, comments to the press, or photos - so its a form of a scavenger hunt. Bits of information are revealed from a news helicopter overflights, private plane overflights, on-the-ground private youtubers, Juan Browne's videos, or DWR's drone videos.

The skyward shot of this image doesn't give many clues to its location - it does indicate where its not in the picture. However, the size of the larger rock in this conveyor pile indicate this rock is more suited for base road building (i.e. like "pit run" - too large for standard paving).

[KC Burke]

I doubt very seriously that the slab work on the spillway would be done with local aggregate.

Local aggregate is used for mass concrete, but often there is too large a percentage of extraneous materials, clays, lignites, and such to have a good mix. Likewise, there is no history on a mix design from the local aggregate.

For durability this needs to be done with the right type of limestone aggregate in a proven mix design.

The RCC could be done with something local but I doubt that such will be the case. I imagine a local batch operation however.

[abb]

Perhaps recycled concrete from the existing slab?

http://www.cement.org/docs/default-source/th-paving-pdfs/sustainability/recycled-concrete-pca-logo.pdf

[mad_as_he$$]

Teichert is a very big local/regional company that operates several very big quarries.

http://www.teichert.com/materials/teichert-aggregates/

[EarthResearcher333]

Hi jpal, Your questions reveal the complexities and challenges faced for a 384 tendon replacement effort. Surely this would be a very specialized skillset requiring an experienced contractor. There are companies that specialize in Dam reconstruction & repairs - including the touted expertise in Anchor Tendon repair/replacement.

Reading through the redacted BOC reports, I didn't see any indicators that there was an intent on replacing the anchor tendons (in this phase of the contract).

There is not much choice in options regarding the density of these tendons. They are strategically placed to distribute the focus of the arc of stress from the trunnion gates. You don't want to "swiss cheese" the contributing structural concrete with alternate drillings. Replacement requires a process to evacuate the tendon & the grout while likely side coring out the anchor "Tee".

However, I believe that DWR is still banking on FDH Velocitel's Dispersal Wave testing results to make any decisions on tendon replacements (DWR states FDH Velocitel's results not expected until Sep 1, 2017). This proprietary technique is still in the "proving out" stage. There could be uncertainties in the conclusions. Below is the efforts taken to be "certain" on 1960's era tendons that include hydraulic "lift-off" testing. Lift-off testing will prove out how much tension is remaining in the tendon (actual psi). Because so many dams have had 50 year old steel tendons fail, there should be an effort to replace all of Oroville's anchor tendons while the "cash is flowing" (copyright KC Burke). I suspect the logistics of getting all of these tendons replaced in a tight schedule is a limiting factor. You must have time to deal with variances to the repair process (i.e. surprises). Logistics require a "parallel" process of replacement. A "serial" process multiplies the repair time. Where are they going to get a large number of skilled outfits that can work on all 384 in "bunches" as fast as possible?

Oroville Dam Anchor Tendons - identical type, age, & corrosion failures as noted in this mini-report - how to determine "certainty" in the state of anchor tendons - includes hydraulic "lift-off" test

[EarthResearcher333]

I agree. Did you catch the discussion of asbestos in the BOC report? Asbestos is part of the geology of the metavolcanic rock complex. I can image the hazards of "crush" dust from these stockpiles. I envision the typical attorney commercials years from now... "Have you lost or have a loved one suffering from mesothelioma from construction at Oroville dam back in 2017?".... :-)

DWR is treating the area as a "contaminated site" including monitoring the air at the work site and nearby neighborhoods. DWR is assuring the public that risk to workers and the surrounding community is minimal.

I'm guessing that is not exactly comforting to the nearby residents - especially when this giant stockpile may be used for access roads throughout the hillside areas along Oregon Gulch Road. These residents are already complaining about the "dust" from existing construction work. Now they have to face asbestos concerns & assurances.

Mercury News Article on the Oroville Dam natural Asbestos:

Oroville Dam: Asbestos found in spillway rock; dust controls increased

[rgb251]

Thank you for correcting my statement Jim 0216. You got it right. NASA management could readily measure Faster and Cheaper with days and dollars. NASA management could not easily measure Better. This deficiency resulted in an accumulation of the risk of a major failure in the Columbia space exploration shuttle System.

There is an excellent book on the Challenger Disaster by Dianne Vaughn: “The Challenger Launch Decision - Risky Technology, Culture, and Deviance at NASA,” published by The University of Chicago Press. I met several times with Dr Vaughn when she was writing the chapters that addressed the effects of the ‘Engineering Culture’ on causation of the Challenger Disaster.

Based on what I have learned about causation of the failures of the recent Oroville Dam Primary and Emergency Spillways, there are many important similarities with those factors that caused the Challenger Disaster. Key similarities include the “Normalization of Deviance” and the effects of the Engineering Culture addressed in this excellent book.

[Jim W N]

Thank you Professor Bea. My gut was essentially telling me that as I listened on my way to work to the on-again, off-again countdown. It was only later that I actually found out about the tragedy.

“Normalization of Deviance”

Sadly, that sounds fairly descriptive of our society these days.

[mad_as_he$$]

Fascinating.

[EarthResearcher333]

“Normalization of Deviance”..Sadly, that sounds fairly descriptive of our society these days.

Strictly from an Engineering environment & engineering organization, should this high level philosophy be kept in context. Just a bit of horse blinders to keep from spiraling into the "lunacy vectors" of a societal context.

Temptation is in every part of life, including engineering. The engineering hero in Atlas Shrugs *John Galt* illustrates the fearlessness & qualities that should drive the moral core of the engineering conscience. Often, engineering organizations have the saying, you need to have older/elder "grey beards" around as part of the group. Why, because these veterans are the heart & conscience of maintaining high standards and maintaining the moral core. Usually, they are fearless, (in the sense of maintaining engineering qualities, with no compromises) and are unafraid of challenging against the temptation to swizzle specifications or "reason away" parameters or outcomes for some type of false benefit. Often, they serve as mentors to the younger engineers.

I've seen engineers get corporate awards for saving big $'s on volumes of reduction of numerous decoupling capacitors on Computer boards, as measured by finding they could meet or beat RF radiated emissions as tested to FCC Class B standards in a computer enclosure. (I'm non-grey - yet I worked on these crisis problems) - I brought up the fact that they just intensified the internal RF emissions into a radiated state where internal mixing of the RF was causing a "chance" complex cancellation & reabsorption in the metal skins of the enclosure. They created a monster in allowing this energy to "develop" & it would find a way out on a cable or seam in a future enclosure modification. Nobody thought of that. (let alone the radical increase of Vcc noise in the power quality in the computer Vcc/Gnd specs). The engineer just went by - the computer was still working - it didn't crash. I could go on for months over wild cases in engineering examples.

This type of engineering creep of temptation or incompetence in design degradations must be eliminated by skilled, experienced, unafraid, leadership heroes within organizations. Perhaps there should be more books written on these heroes to help raise awareness of this critical important moral core.

I will say one thing, it takes a special breed of person to be fierce in these qualities. Sometimes, it is within the quietest of personalities (excuse the term - nerd).

- - - for those interested in "Normalization of Deviance" - snip from wiki The Challenger Launch Decision:

Diane Vaughan developed her theory of the normalization of deviance in The Challenger Launch Decision. She details how, during the developmental phase of the Space Shuttle Program, the normalization of deviance resulted in a dangerous design flaw in the design of the spacecraft. The group that was assessing the joints on the solid rocket boosters conducted analysis to find the "limits and capabilities of joint performance. Each time, evidence initially interpreted as a deviation from expected performance was reinterpreted as within the bounds of acceptable risk"[7]. The acceptance of this risk led to the Challenger exploding on the morning of January 28, 1986.

NASA and Morton-Thiokol suffered from the normalization of deviance when assessing the safety of the SRBs. Diane Vaughan states, "As [NASA and Morton-Thiokol] recurrently observed the problem with no consequence they got to the point that flying with the flaw was normal and acceptable"[10]. On January 28, 1986, the normalization of deviance within the two organizations contributed to the loss of the Space Shuttle Challenger and the seven astronauts on board.

[EarthResearcher333]

Milky White Substance + Foam - Originating at Spillway & Feather River

A Milky White substance and Foam observed when the Oroville spillway reopened April 14. I did some research & found this. Overflight video, in the morning of April 15 by locals, reveal the origin is within the spill turbulence from the canyon outflow.

Deflection of this flow, on the opposite side of the river bank, reveals the milky white substance & foaming to branch both directions (upstream and downstream based on the riverbank backstop).

A second overflight, closer to mid-day, reveals the material subsiding. This indicates it was an initial condition from the spillway turn-on and lessened when "washing" purged the source.

The Central Valley Regional Water Quality Control Board was notified and they took samples to determine the source of the foam. (see article link). The results won't be known for 2 weeks.

Not sure why, but, the agency supervising engineer, Bryan Smith, commented that "It might be 'foaming agents' in the water, or natural causes might be found. Smith said decaying plants and algae can cause foam in water, or a change in water temperature. Pollen can also appear like foam, he said".

I suppose that they are not aware of the video of the overflights. If so, I believe it would immediately lead them to investigate if all of the myriad of coring/drilling & drill mudding in the Upper Main Spillway may be the cause. Keep in mind that there is likely a fractured rock sub base in the Upper Spillway. Core Drilling could have injected an amount of material used in the coring process. Then there is the re-sealing of the core holes to ready the spillway for re-opening. The underdrain system beneath the slabs would easily wash and port the fluidic leftover material into the sidewall drain chutes.

Hope they used an "eco-friendly" material. We'll see what the test results come out to be. btw- DWR may have had a hint of this early on by observing the water drains… unless the "foaming" required turbulence & mixing of minerals in the canyon..

= = Mercury News Article snip

Oroville – Foam floated downstream and made circles on the water last week in the pool below Oroville Dam. Water quality experts are trying to determine why.

Oroville Dam: Mystery foam appears below damaged spillway

Mystery Milky White substance & foam flowing in the diversion pool caught the attention of locals. Central Valley Regional Water Quality Control Board was notified & samples taken.

Milky White substance + Foam observed originating at spillway turbulence from canyon - outflow from Upper Main Spillway. Material goes upstream and downstream from bank flow back pressure hydraulics.

[Jim W N]

Isn’t this water flowing over a bunch of shotcrete they recently laid down? If so, my amateur guess would be the force of water scouring across the newly sprayed shotcrete.