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]

>>Massive Concrete Chunk: Forensic Main Spillway "Blowout" Failure Evidence?

A Large Chunk of Concrete at the bottom of the Main Spillway may yield clues to the main spillway failure. This sizable chunk of concrete is most likely a "Backfill Concrete" chunk. See blueprint construction drawings (Backfill Concrete) at:

http://www.freerepublic.com/focus/f-news/3524221/posts?page=1830#1830

Why this chunk is so valuable in forensic information is that it reveals critical construction insight. The most important issue this piece reveals is that faulty drainage issues may have been created in their "Backfill" process AND an unforeseen assimilation of gravel in the "top" slab pour.

How? (Here are the important "clues" - indicators): Note: This information is "early forensic data"…

1. This chunk has a flat surface (likely was vertical). The presence of the load transfer "dowel pins" indicate that it adjoined with a sidewall section.

2. This chunk reveals that the top main slab spillway concrete pour was directly on the top surface of this large "backfill concrete block".

3. The irregular bottom of the chunk reveals that it likely was upon a rock surface (thus the need to fill a void to get to the main spillway "grade level").

4. This chunk reveals that there is no observable "drainage" layer or seam (gravel layer) to allow underflow water to be collected into the drain pipes. (i.e. this chunk is solid - layer of concrete on block of concrete).

5. The "flat surface" of this block (item [1]) indicates that the sidewalls were poured first. Thus the the other part of the "void" "backfill" in the flat area of the main spillway formed the flat surface for this later pour (2nd void fill pour in the MS followed by MS top surface pour).

IF 1-5 are correct, there are forensic questions that arise: (A) A vertical "seam" was created that would allow water to penetrate between the two halves of the "backfill". The drainage system design would not be able to capture this water. Water under pressure could go down this seam and below into the lower base rock. (B) If the lower base rock has fractures, the water would continue to penetrate, including laterally deep within the foundation rock. (B) The lack of a "drainage" layer [4] could exacerbate (A). ( C ) Hydraulic expansion and contraction from great spillway forces via the water penetration could further weaken the rock below (penetration into small cracks in the rock). (D) Voids could have formed from gradual crunching of the effects of (A to C). Thus stress would have increased in the main spillway slab, leading to potential or eventual shifting of the surface (heave or slump).

KEY speculation: The fact that the large chunk has the intact remains of the main spillway slab + the concrete backfill is a strong indication of the bonding forces between these two. The evidence of the "seam" + the strong bonding forces indicates that the intended thin gravel drainage layer was assimilated in the top slab pour. This would be critical, as this construction "process" would have messed up the drainage design for the parts of the main spillway. How? Instead of an easy path to drain, high pressure water would have been forced into deeper sidewall seams & the underlying rock. Hydraulic expansion & contraction forces would be problematic.

KEY Point: The "blowout" failure region was noted prior to having "missing" waterflow in the sidewall drains. This "Large Chunk" highly indicates that drainage would not have been optimal (to say the least) in a collecting drain pipe & gravel seam system.

[LucyT]

Check out # 2,061 .

For further information, Please read # 2,015 - I meant to ping it earlier...

Here's the link:

http://www.freerepublic.com/focus/news/3524221/posts?page=2015#2015

Thanks, EarthResearcher333.

[KC Burke]

I guess my comments from a couple of days ago about slab sub-grades not being uniform were correct but even I didn’t expect to see sub-base eliminated by lean concrete slop fill. The hydraulic build up below the slab portions without drainage produced what I speculated was a primary cause of the large failure. Cavitation bubble may have damaged poor joint repair, but they didn’t do this damage.

[The Westerner]

A concrete forensic detective, our EarthResearcher. It looked like a massive chunk of concrete to me. Earth explains what it all means. Highly recommended reading.

[The Westerner]

A concrete forensic detective, our EarthResearcher. It looked like a massive chunk of concrete to me. Earth explains what it all means. Highly recommended reading.

[EarthResearcher333]

This piece may turn out to be invaluable for actual construction forensics as it hasn’t been pulverized/destroyed into debris as in the river. IT HAS been surface worn from spillway flow containing small rock pieces. You can see the surface damage this from a “small rock sand blasting effect” on the huge aeration block surfaces.

Only would a close up inspection reveal better answers. IT is possible this “backfill block” was further down from the failure area. It may just have happened to be hydraulically ripped out from the continuing damage due to the high pressure turbulent hydraulic scouring.

In any case, a large backfill chunk, that hasn’t been destroyed (evidence) may provide great information. (it may take a long time before any official information is discussed or released - early analysis, especially without “hands on” access is fraught with potential missing information.)

Re: Cavitation damage: Keep in mind that a sub-structure erosion void may have created a recurring stress at the slab top region. This stress could have caused complex crack/horizontal void pressures (which could lead to a ‘chip’ off of the surface to break). Then cavitation damage would exploit this defect, leading to more exacerbating conditions - including an eventual shift in a slab if there was a sub-structure erosion/void present.

[EternalHope]

This is the best place I have found on the net for information on this still developing situation.

I have very little to add, other than many thanks to all for the excellent work!

[Jim W N]

Thanks ER. With the worker-ants in the foreground, you get another perspective about how surprisingly giant this whole thing is.

[Jim W N]

Nice deduction and investigation guys. It always helps to have a body at the scene of he crime.

[bgill]

Guess we know where Trump’s infrastructure monies are going. Never mind that it had already been funded but CA had more pressing uses for it like illegals and green energy.

[SGCOS]

I've never seen rolls of duct tape that big!!

[KC Burke]

Oh I know. I was just enjoying the fact that as an old retired construction fellow, I was 30% there sitting at my computer.

The first time the spillway was stopped to examine the damage, this big chunk was not down in the teeth of the dispersion blocks. It appeared later. That says to me that it is a slab torn loose subsequently down hill from the initial large opening. It is however a good record of the variations we have in the spillway sub-grade and its lack of uniformity.

[KC Burke]

On the “Sluice Box” article site I love how they just had to throw in the reference to Free Masons.

LOL, they couldn’t resist.

[bgill]

If the entire dam goes, billions of dollars of gold will be unearthed.

Good. Pan the gold for the money to pay for the repairs.

[Jim W N]

Very interesting.

The name “Oroville” also looks like it could have been derived from the word “ore” as in gold ore.

[Jim W N]

Free Republic - one-stop shopping. You can learn so much here about just about anything.

[Jim W N]

Hey, if all else fails, they can always duct tape everything!

[WildHighlander57]

Mt. Ophir

http://explorehistoricalif.tripod.com/xplorhistcal/id10.html

Boswell’s Bar

http://latitude.to/articles-by-country/us/united-states/158576/bidwells-bar-california

Ophir City

http://www.theinfolist.com/html/en/ophir_city,_california.html