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

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

[janetjanet998]

The California Department of Water Resources issued a sudden evacuation order shortly before 5 p.m. Sunday for residents near the Oroville Dam in northern California, warning that the dam’s emergency spillway would fail in the next 60 minutes.

The Oroville Dam is the highest in the nation.

[EarthResearcher333]

Kiewit batch plant installation - Boat Ramp parking lot @ ES - Water Feed Hose run to Reservoir

Photo taken Sunday May 21, 2017. Shows they are working weekends. Painted "Kiewit" logo prominent on unit. DWR metadata on photo says construction work to "ramp up" May 22, 2017

I suspect a 2nd plant may be setup on the east side of the Main Spillway were there used to be a large building in the original 1960's construction of the spillways & FCO headworks. Piles of presorted aggregate and materials have been conveyor belt "piled" at that "staging" location.

Kiewit batch plant in the Boat ramp parking lot near the Emergency Spillway. Large Black hoses observed running along the face of the Emergency Spillway to the Reservoir. Inferred to be the intended water supply for the plant.

Possible 2nd batch plant location on the east side of the main spillway. Stockpiled material "cones" shaped from depositing typically by a portable conveyor unit.

[The Westerner]

ER333, one man cannot alone fight the Leviathan. If this is causing you heart trouble, please take care of yourself. We have to believe that rational engineers are not going to allow that dam to fail.

[EarthResearcher333]

Serious Headworks Design Flaw - Inducing Shear Cracking in Gate Piers - Risks Stresses in Trunnion column

An overlooked design detail in footing loading upon the substructure noted "competent rock" at the FCO Headworks and Spillway Bridge "Lift" column reveals a "Diagonal Cracking" or "Shear Cracking" Flaw mechanism. This "Flaw" risks a "Failing" of Gates 1 and 8 Pier supports via a potential shifting of the Trunnion pin axis alignment to the Radial Gate Skin Plate radius. A "shift" in the axis alignment is amplified by the radial gate radius length. Thus a small "shift" could "bind" the gate. Anchor tendons, below within the pier columns, traverse across this shear cracking "plane" centered at the corner of the spillway bridge support notch. Thus, the anchor tendons will absorb "Shear Cracking" forces transferred from crack expansion. This would create an additional load to the Anchor Tendons beyond the original design loads of Radial Trunnion Gate Hydrostatic pressures in flood release operation.

The overlooked design detail was the "footing" settling forces upon the "competent rock". The FCO Gate Structures (Piers, Headworks, Footing) are all secured with reinforcement (rebar). Two FCO Gate Structures were built with a contraction seam where these meet. Gates 1-4 form one FCO reinforced Monolith structure, and Gates 5-8 form the second reinforced Monolith structure. Both have their own individual large reinforced footings constructed of thick concrete as further anchorage. However, the spillway bridge "lift" columns (5ft+ thick) have their own footings separate from the FCO reinforced Monolith structures. Blueprints do not show any design of footings wider than the original width of the Bridge Abutment (5ft thick, thus 5ft wide in drawings). Differences in settlement of the Bridge Abutment "lift" column vs the FCO Gate structure from - Phreatic pressure, "rock competency", and heavy bridge crossing loadings, all could influence the forces concentrated into the corner of the notch in the Pier. The evidence of the large diagonal cracks originating at this corner in the notch confirms the presence of a "shear force". This is the exact location that this design flaw would manifest if the Bridge Abutment were to "settle" deeper than the FCO structure.

DSOD Inspection reports confirm that both end piers have the same "Shear Cracking" problem at the same corner location(s). DSOD 1998 Inspection report also notes that this dual "shear cracking" condition has been noted in prior inspections. Thus, this "flaw" cracking result has been developing for many years (& prior to 1998). This means that for 19 years this issue either was not considered a "structural risk" to the Headworks by DWR, or that the issue may not have been understood, or ?.

The immediate "arresting" of this Shear Cracking would require the shutting down of the spillway bridge and removing the corner load forces on the end pier corner notches. With all of the extreme tonnage of emergency repair work loads across the spillway bridge, this likely has risked further aggravation of the shear cracking flexing on these existing cracks. With nothing but red paint as a mechanism in addressing these "cracks", and all of this heavy stress loading placed upon this "flaw", is there proper engineering judgement being applied? DWR has placed metal plates across these end junctions, but should they even be operating this bridge knowing that they are risking further structural damage potential? (including stress loading the end pier Anchor tendons).

"Flaw" in headworks design. Different settlements of the Bridge Abutment concrete support column between the FCO Structure will create a focus force in the corner notch in the 5ft thick Gate end Piers 1 & 10. This is where DSOD inspectors are watching "Shear Cracks" grow."

DSOD Inspectors documenting the "Shear Cracking" at the corner notch of both end piers. Cracks have been present and growing for 19+ years. Why hasn't this "flaw" been figured out and addressed? (instead of using red paint).

[EarthResearcher333]

After an information "tip".. I've been moderately puzzled over the large block of concrete at the end of the spillway chute blocks. In going back to re-analyze the "large concrete" block -that was pushed down to the end of the spillway- there looks to be evidence that this large block may be a 6ft deep "void" fill.

If true, this provides an answer as to how a couple of sidewall drain outlets could have been completely plugged. The blowout failure area is in a location that has been revealed to have highly weathered rock. Upthread post (copied here below for a "combined post") identified a "diagonal" percolation seam of water near the blowout failure region of the spillway. This water presence infers a history of a spring like water presence. Thus, this would note that there could be a highly erodible area of "weathered rock".

Upthread posts have noted "fixing" of the spillway in the areas where 2 sidewall drains were not functioning. The BOC has also verified that "washable" material was underneath the concrete slabs where piping water flow could wash and erode. If "escape" channels of this "pressurized" washable erosion effect developed, to where material was being eroded and carried away underneath the sidewall berms, then large voids could develop that would not be detectable from a surface observation. The most vulnerable locations to this "effect" would be the highly erodible weathered rock near the seam of water was in the early construction postcard photo.

The information "tip" noted that the larger voiding was near 6 feet deep. If this size of void or even a shallower size void occurred underneath a drain, there is the possibility that the "coupled" drains could fall into the void. A drain coupling would then be fully "open" at a disconnection point. Subsequent "void repair" in pumping in grout/concrete mix could likely flow into the "open" drain pipe and including flowing into the longitudinal collector drain. This certainly could plug a drain if the internal pipe voiding fill reached the last longitudinal drain coupling junction. (note: the BOC had noted of "holes" cut into the slabs for repairs - perhaps these "holes" were to provide a volume of concrete emplacement such as to fill a large void).

Another possibility is if tree roots assisted in this "voiding" disruption of the drain pipe disconnect. Grout "void fill" repairs could enter into the drain pipe and end up in the longitudinal drain & seal it off.

The key tip to this "large block" of concrete is the clean seam of the slab line and the bonding concrete below. A somewhat good bond would be necessary for the slab layer & under material formed block to survive a push near 1000+ feet down to the end chute blocks. BOC reports and early design photographs (below) reveal that a "grade layer" of material was placed before the drains were laid and then the concrete slabs were poured over. Only by a pressurized "cleaning" or washing of the underside of this material below the slab could a sufficient bond of a "void fill" repair attachment form. The irregularity of the slab underside surface would also affect the resulting bond.

Original design specifications noted that concrete fill to "grade level" was to be done in areas of less than competent rock. However, the photographs do not reveal any surface areas that are "concrete" in sections - only a uniform "grade fill" of a material that has percolation water filtering within. The photographic evidence of a number of view angles of this large block also notes the absence of any anchor rebar that the original design specs noted - IF this was a "fill to grade" concrete layer. Further examination of this large block reveals that the fractured face is slightly curved. Thus this likely isn't a section that was a junction directly abutting a sidewall seam. DSOD Inspection report did note a "drum" sounding in the spillway during inspection. Apparently, a method of dragging chains were used to "sound" the surface of the slab. I'll have to dig back to find which year and date that DSOD "drum" sounding was reported. But, this reveals that there has been an awareness of voiding to the degree that should have triggered further investigations - i.e. rather than "pumping" until the slab "gas tank" is "full".

Possible 6ft "void" repair fill from "blowout" area

prior upthread post:

Subsurface Seam at Blowout Failure location gives Strong Clue

A 1967 postcard image reveals a natural "Water Percolation Seam" at/near the Blowout Failure location. (note: the postcard was digitally enhanced to filter the "texture dots" to provide this clearer forensic image).

As this photograph was taken prior to the pour of the spillway concrete slabs, the image reveals the "grade" construction of which the slabs were to be emplaced upon. This forensic "seam" presence provides geologic insight, especially regarding the question of "Where's the Missing Water?" from the spillway drains in this pre-blowout failure location. The photograph also provides insight into how "un-captured" waterflow in the sub-par drain design could "wash" a void layer between the bedrock and the concrete slab pour. The spillway "chute" design has embankment fill. There were no signs of embankment erosion near this failure area. The only sign was a preference of large tree growth (roots + growth = subsurface water). The "Seam" answers the question of a "deeper" subsurface flow capability. Over time, the erosion of this flow could increase the underslab voiding.

Given these conditions, the deep waterflow + erosion could have created substantial voids (note: persistent spillway "missing water" at equal levels of the "working drains" observed flow rates = a high capacity deep flow "seam" likely was created in time; exploiting this location's natural formation). Each time the spillway was operated, it eroded and enlarged a void area. Until a higher structural stress condition was applied - such as a higher flow rate - did the right conditions of the voiding stress the failed slab to its limits. Part of this equation is the other dynamic stress condition of hydraulic jacking (one is up the other is down).

Subsurface Seam at Blowout Failure location. Photograph provides insight into how "un-captured" waterflow in the sub-par drain design could "wash" a void layer between the bedrock and the concrete slab pour.

[abb]

If they pumped grout beneath the slab to fill a void, the sheer quantity of grout used ought to be a giveaway that something’s not right.

[meyer]

That “percolation” seam, the wet crack across the spillway, should have been a hint that there was something wrong in that spot. A hint large enough to maybe dig that area up, asses and then redo it. And maybe it was to some on the job, but the warning sign never made it up the ladder for some reason or another.

[EarthResearcher333]

DSOD 1/12/2000 Inspection report:

Found the "Drummy" soundings on the concrete in the Spillway. note: "drummy" soundings are from either dragging chains over the spillway slabs & listening for "hollow" types of sounds that occurs from open voids below. This is from a 1/12/2000 DSOD report.

Amazingly, the Inspector writes that "No treatment is proposed until they are damaged by a heavy flow". Talk about prophetic. This statement could be the "poster child" sign hanging from Engineering => "NO TREATMENT IS PROPOSED UNTIL THEY ARE DAMAGED BY HEAVY FLOW"

Another astounding finding is that DSOD discovered the cause of all of the "chipping" "spalling" on the bridge abutment ends. The original design never put in sliding bearing plates. Thus the bridge slab will rub "concrete on concrete" in the expansion overlap seat. Inspectors measured the size of the expansion seat as 11 inches. Worst section losses of "chipped" away spalling of the abutment support concrete was measured at 5.5 inches. The inspector calculated the required support overlap is 6 inches. This would be -0.5 inches below the required support. (note the Inspector's math of 6.5 inches of bearing left is in error - should be 5.5 inches - skipped a digit). DWR should not be using this bridge. It is a highest level Category 1 Potential Failure Mode (PFM). THIS WAS 17 YEARS AGO. THEY ARE STILL PAINTING THE SPALL AREA TO WATCH THE CHIPPING CONTINUE. Amazing.

Note: PFM in this case would be from a heavy construction vehicle inducing a collapse of either end of the bridge at the chipped away abutment support. The heavy vehicle would crash down directly on top of the Radial Trunnion Gate anchorage, the Radial Gate Trunnions, and the Anchor Tendon assemblies.

[abb]

In a sclerotic administrative system that is the Cali DWR, who wants to be the whistleblower? You’d be labeled a sh!t stirrer, a busybody, someone who can’t ‘fit the mold.’

[abb]

They’re beginning to jackhammer out the old spillway pieces.

https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/I0000yQYBPEJZj2M/DK-oroville-spillway-1337-05-22-2017-jpg

[EarthResearcher333]

Possible location for a large batch plant on the east side of the Main Spillway (adjacent to the erosion canyon). Multiple vertical "large tanks" with bottom footings may be batch plant "silos" used for aggregate or cement feeding via the conical bottom design. Typically, these "silos" are elevated on extensions or are mounted on a structure to feed to the "mixer".

[jpal]

ER333: you always have interesting, well researched, and thought-provoking posts. Again, many thanks.

Regarding the concrete chunk you reference, Bill Crowle from DWR did say that the spillway slab was 6 foot thick in sections, and that chunk does appear to be from one of those extra thick sections.

On one hand, I’ve worked enough construction to know that no contractor will lay down 6 feet of concrete if they can get away with a 1 foot slab on top of whatever type of (erodible) base material they were using. The contractor pays for every truck load of concrete, and that comes out of their profit margin, which they’re generally rather concerned about. This would be an argument for there being a 1 foot base slab, with the rest mud jacked in years later, as you suggest.

On the other hand, from the picture, the entire chunk of concrete appears monolithic with the same mix design, and I couldn’t see two lifts of concrete placed a couple decades apart tumbling 1000 feet downstream as a monolith. I think we’d need a closer examination of that chunk of concrete to make the call.

If they did mudjack the slabs, it seems plausible this could plug up some of the diagonal under-slab drains. However, I couldn’t see this plugging up the longitudinal side collector drains. This would be too easy to check for, even in the pre-borehole camera era. You just pour water down the upstream vent tube, and if it doesn’t come out the downstream sidewall port at the same rate, then you know you have a clog between the two. DWR may not be the sharpest crayon in the coloring box, but you’d have to be a total idiot to let a spillway contractor walk away from the job with a paycheck without checking for a clogged drain.

If a tree root was a contributing factor to the drain clog which precipitated the spillway failure, and we know the drains were under high pressure, then it seems plausible that the pressurized water could escape along the root pathway through the fill to the side of the spillway. This would provide a high-volume escape route for the water, taking more more base material with it. Some pictures appear to indicate the side of the spillway was blown out before the major slab failure.

If the pressurized water had no escape, it would push the slab up, “hydraulically jacking” it. If the water had an escape route, it would go longer be pressurized and spurting out the sidewall, but eroding underneath it, and the slab would fail downward. Up or down, the slab failed one way or the other.

A contributing factor to both the spillway failure and FCO structure problems which hasn’t been examined in this thread (to the best of my knowledge) is concrete shrinkage. Some old mix designs would shrink quite a bit. With the extra large slabs they were using on the spillway, the expansion joints could pull apart, letting more water under the slabs than could be caulked out. This could also contribute to why FCO is now 5 1/2 inches shy of the fixed foundation at the abutment, and cracking at the seams.

To build a R/C structure and that needs to function reliably for a 100 years or so, I’d go with an expansive mix design, using a type K cement. This has Ettringite (calcium aluminum sulfate) added. There are type K slabs which are approaching 50 years old, the same age as Oroville, that are still in almost perfect shape with no cracks or joint issues.

A plausible hypothesis as to why a tree root may have grown adjacent and then into the drain at the blowout failure location is that there was a natural “Water Percolation Seam” at this location. The native geology of the area appears to contain a great deal of fractured and erodible rock with many fissures that water could percolate through. It is also plausible that such a seasonal “Water Percolation Seam” could be injecting moisture into the side of the dam, creating the (apparently) seasonal “Green Spot”.

[meyer]

I agree - looks like they’re setting up a concrete operation. I think that they’re setting this one up possibly for trucks, based on what looks like a platform being build just above the large tank towards the left of the image. It looks like where a loading mechanism might go.

It will be very interesting to watch how this job develops over the next few months. Looking back, despite all the serious issues that need to be attended to, they have done an enormous amount of work in the last 3 months with getting things somewhat under control.

Funny how productive even government can be when panic sets in.

[EarthResearcher333]

"Funny how productive even government can be when panic sets in.

I give more credit to the contractors.

DWR had plenty of sign of issues & did nothing about it. Reading through their documentation on the issues, PFM's, DSSMR's, they were going through the motions & not maintaining the spillway. DWR has sliced all of the piezometer tubings and hasn't placed a single new Piezometer in the dam - even when FERC has repeatedly been asking them for years to do so.

The failure finally caught up with them. It was just a matter of time in their operations and non-proactive work that PFM's & DSSMR's were designed for.

[EarthResearcher333]

Hi Jpal, I'll be up front. I take issue with your history of presentation of positions which somewhat lack a hard reference of a body of observable evidence (i.e should be presented in researched detailed and thorough evidence - while other researched and detailed evidence has been either ignored or tossed aside). A position should not be influenced on "boat buddies", "their alcohol state", nor from "I guess I don't go by there too often myself..", "someone would be an idiot if", etc.

If you want a high level technical discussion - rise to the level of the body of research and thorough evidence in totality and fully recognize the body of what has been researched and presented. Otherwise I would rather not engage.

Given this, let's just take one issue at a time.

Let's leave out "crayons", and "idiot contractors" getting paid while assuming they were supposed to do something...euphemisms.

Did you read post 3705? Where the DSOD Inspector stated they found voids in the spillway by "soundings" (drummy patches)? Did you read the following statement by the DSOD inspector "No treatment is proposed until they are damaged by a heavy flow"?

(1) The cavity size to create a "drummy" echo sounding on the spillway concrete has to be of enough significant "void" volume to provide the dB acoustic response back through concrete to be heard. Do you agree or disagree? (yes/no)

(2) The DSOD Inspector found more than one area (acoustic drummy patches) that generated the significant enough dB acoustic response back through the concrete to be heard and noted. Do you agree or disagree? (yes/no)

(3) The DSOD Inspector identified that an action ("treatment" and/or remedy) was only going to be acted upon "until they (acoustic drummy patches) are damaged by a heavy flow". Do you agree or disagree? (yes/no)

(4) If DSOD - the Inspectors, who should be identifying the corrective actions that should be taken to the dam owner/operators (DWR) - are being told that "nothing will be done until these areas are damaged", does this in any way identify to you that something is severely wrong with the curtailing the authority of the Inspectors? Do you agree or disagree? (yes/no)

Thus, would this give you any indication as to the pattern of operations and decisions that identify how serious problems develop and are not effectively investigated by DWR/DSOD - agree or disagree?

[EarthResearcher333]

Correction: Post 3707 (3705 was the “reply to”).

[meyer]

I give more credit to the contractors.

Good point. I was thinking more in terms of the working class rather than the commanding "political" class, but in hindsight, most of the workers dealing with the dredging and shotcreting and all that are contractors.

I was thinking of here at TVA where we have a motto that we accomplish much despite management. And really, it's amazing how people DO get things done when TSHTF so to speak. Problem is, that effort goes away once the catastrophe is past.

[EarthResearcher333]

Further points:

I have refrained from commenting in many instances in past posts: But I will now bring a few to light.

How can a person demonstrate competency in a subject discussion when acting as if they are "joining in" on a technical discussion "on par", when the statement of using LIDAR infers incompetency in the subject matter at hand? (Post 3659) jpal: "A high res 3D profile of the dam should be generated from terrestrial Lidar"

The best digital processing of LIDAR data has a resolution of 3.9 inches (even without the additional grass vegetation modulation of the data since it is "reflected light based readings"). To detect any "differential settlement" profiles in a one, two, or multiple year span (two separate readings to compare against), you must have millimeter accuracy. Only satellite Interferometric Synthetic Aperture Radar (InSAR) has the ability to measure to millimeters. I would say that a millimeter range near 0.03937 inches is much more definitive than 3.9 inches (99x).

Learn what you are talking about before joining in as if you know.

PavewayIV revealed this insight "clue" in that he was unable to find LIDAR mappings of a dam (post 3573). That's because you cannot get the accuracy to measure the precision settlement that is necessary from the course LIDAR method. (see Svartevatn dam measured using Satellite InSAR with rates defined in millimeters).

Another subject:

You wanted to discuss a technical array of microprocessor based sensors to emplace in the new spillway. Fine. When presented with very detailed and technical challenges to high-reliability systems regarding modern day microprocessors, supporting supply electronics, and the C++ compilers & execution code tree verifiability... No response. I didn't even bring up the survivability issues with arresting ESD life & degradation protection from lightning discharges that undoubtably occur from thunderstorms that could strike near the spillway.

If a person wants to enter into a discussion at a level that they come across in detail to discuss - Learn what you are talking about - or if you need help, engage to ask questions to come up to speed.

[EarthResearcher333]

More Issues:

You say jpal: "Bill Crowle [sic] did say that the spillway slab was 6 foot thick in sections,..."

Yet you provide no proof to 6 feet in Bill Croyle's statement. In fact, the only information is a 4 foot to 5 foot value from "coring" of the Upper Main Spillway. (see information from metabunk where Dan B. contacted DWR to get further details): (https://www.metabunk.org/oroville-spillway-investigation-and-repair.t8640/page-3)

- - metabunk clip: I asked DWR the week before last to expand on the claim about the thicker concrete. Here's part of an email exchange with the person who's been put in charge of responding to most spillway questions:

Q. Director Croyle mentioned that drilling on the upper spillway has revealed areas with 4 or 5 feet of concrete. How extensive are those areas? Earlier reports from Board of Consultants and others stated the slab was 9 to 15 inches thick (depending on placement of sub-slab herringbone drains). Were those reports essentially accurate?

A. A number of holes have been drilled in the upper portion of the gated flood control spillway and more will be drilled in order to assess geological conditions. Some bore holes show concrete that is four to five feet thick, some do not.

​ And that's all the department's communications apparatus chooses to say on that subject. I don't know if you could be less informative if you tried, but I'm guessing that's precisely the department's intention. It would be easier if they'd just say "take our word for it."

= = end clip @ metabunk

Given this, you claim: "..and that chunk does appear to be from one of those extra thick sections".

So how did the Upper main spillway suddenly break off a chunk and hurl itself down to the end of the bottom of the Main spillway without anyone noticing? AND while it was on the way down, this chunk, after being "cored", grew to 7.5 feet in thickness?

You see... I can disassemble your reasoning & statements swiftly.

Bill Croyle's 4ft to 5ft statement was a PR response to pressure from the thin design issues & proven thin areas of the near 5 linear miles of cracked drains. Did it ever enter into your thinking that the thickness of the slabs, when recently cored, may have been affected by all of the "void" filling that has been going on for years in the pressurized erosion washing conditions under the spillway? OR was it possible that the 4ft to 5ft coring thickness statement was from testing the Upper Main Spillway sidewall footings? (a highly deceptive answer in a PR sensitive distrust of DWR).? I could continue to disassemble the rest of your reasoning & statements in the post. But I will wait to see how you answer on all of these post items.

[meyer]

Re-inspecting the images you provided, would it be more likely that they built up a flat base with concrete, then poured the slab over top, or did they inject/fill under the slab at a later date. Injecting under pressure indicates what you spelled out - that they may have inadvertently filled or blocked lateral drain lines at the point where the failure took place.

But even if they pre-poured concrete to level the ground prior to laying down the deck, did some of the weathered rock around the concrete pour wash away and cause the drain pipe to fall/move so that it was no longer piping water to the side drains but further undermining the area.

It’s pretty evident either way that that chunk has 2 separate pieces (perhaps anchored together even).

Half deducing, half speculating here.

[EVO X]

If a person wants to enter into a discussion at a level that they come across in detail to discuss - Learn what you are talking about - or if you need help, engage to ask questions to come up to speed.

This is one of of the best threads ever on FR. Thanks for sticking around and providing your insight.