Juan, at first I didn't think I would care much about this dam fiasco, considering I live in Michigan. The more I watch your channel updates, I have found myself more and more intrigued. This interest is because of how you are reporting it. Your insight and research is a common sense look at the realization our aged infrastructure in this country is in need of attention. Great job.
Charlie since you live in Michigan I can assume you have gone to Meijer to buy produce lately. If you have in the winter you will notice that most of the produce you buy comes from California. This dam feeds the aqueducts that supply water to the farms for the produce we buy. That is why this dam is so important nationwide. Without this dam working properly we would lose a good portion of the produce we buy as a nation.
Money is the answer. No one behind it. Where do we spend the money? Most of the Federal budget is spent on Pensions, Health Care, Education, Defense, Welfare, Home Land Security, and Transportation. One or all needs to be cut to pay for infrastructure upkeep. One less Aircraft carrier maybe? Fewer Teachers? Tough choices.
we have aging infrastructure because those in charge of the budget forgot that everything has a service life ... therefore continuous maintenance is needed or thing fail ...
Charlie Brown I'm in the UK and I've gone well past the boredom stage thanks to Juan. I was border line bored with the news channel reporting when I discovered Juan, now I'm here for the ride!
Mr. Brown, I want to thank you for insightful reporting on the Oroville Damn issue. I caught a very brief mention of this on the national news and out of curiosity searched RUclips for more information, where I found your channel. I found several other channels related to Oroville, but yours is the most captivating, professional and well produced of all of them. I liked your exit music and am really into Aram Bedrosian now. I briefly lived in southern CA for a short period and have visited North CA several times, but am now on the south east coast. Even though I am far away, this topic captivates me, as I am a civil structures buff (love to visit Damns and such all over the world). Please continue this series through completion of all the repairs.
Myself as a Commercial and Industrial Electrician for 30 years, you absolutely nailed it with this report! The evolution of building standards have come a long way since 1965... you can really see the deficiency in the original build design from that era compared to what the newer Code Standards of today. Great job Mr. Brown :-) I have been following your work since your first video... looks like a second career as a consultant... lol
Great job as always Juan. As a civil engineer, I enjoy all the content, including technical data you provide on the Oroville issues. Educational, and matter of fact.
Methinks that the vegetation growing near the spillway was an indicator of how much water was leaking from under the spillway.. Opportunistic seeds take hold where moisture is present, after all.
Wow, there was so many warning signs. California officials have some serious explaining to do. I can't wait for a full length documentary about the Oroville dam spillway failure. A lot of awesome hd footage has been collected, hopefully whoever produces the first major documentary uses Juan Brown as one of their main sources and consultant.
I would also like to see more investigation about the cavitation that occurred on the spillway. Cavitation is literally one of the most destructive forces of nature. No material is safe from the energy release of the collapsing bubbles. Not even tungsten carbide or diamond. The only way to stop the destruction is to design a way to keep the low pressure bubbles from ever forming . I am interested to see how the new modern spillway design will be able prevent cavitation
For the record cavitation is not air bubbles, that would be aeration. Cavitation bubbles are the vapor form of the liquid in question, in this case steam. A low pressure zone causes boiling and then the vapor bubbles collapse back into liquid. The collapse causes a shockwave that causes the damage.
Daniel Armstrong The kinetics low pressure make literally the concrete boil ... That's it . Even the tiniest bubble become blowing material ... It happens on steel made ...
No, there is no air in cavitation. As Mike Cowen points out, adding air can prevent cavitation. Cavation bubbles can kind of be thought of as vacuum bubbles. They are not actually a vacuum because, as Daniel Armstrong said, they are filled with water vapor. But, if the water temp is 60 F, then the pressure in the cavitation bubbles is about 0.07 psi. While not a vacuum, that's a fairly low pressure.
+blancolirio Not only, on fluids pump "steel made" could be the fluid itself turn in gazes phases ... There is not that much "air" in gravels concrete like builders try their best to eliminate it, nor in metals alloys ... Use ore water pump and it would be the same ... It's a kinetic energy phenomena which have no "regards" to the raw material used ... No wonder it's the same phenomena astronoms called black holes ... It's kinetics ... What that the point ? You naughty brained Damn shaker !
Juan, thanks for your excellent presentations. Incidentally, cavitation isn't air bubbles. It is caused by low pressure, a vacuum, causing the water to vaporize, or boil. The bubbles are water vapor, not air. You are correct though in that when the bubbles collapse they cause a pressure spike that can damage, concrete, boat propellers and powerhouse turbines.
My dad was a structural civil engineer for South Carolina Electric and Gas and I grew up going to jobs with dad and he'd explain what they were doing and why. Orville Dam is an example why dad always over engineered his jobs. He said he never wanted a structural failure to come back on him. You did an excellent job of explaining the independent report. Dad would have approved.
Thank's for the Stellar Transparency Juan. 1:55 Me too! 6:55 weakened planes. 8:40 no select gravel below said pipe for support cradling. Even you're home's City water meters have @ least 4" below & outside it's edges to insure water junction support. -Bet they don't utilize the same round aggregate sub-base fill as before. -Change Orders needed for the original plans are known to most bidders & affords them to leave money on the table in order to win the lowest bid. -These logically Persuasive future Change Orders eventually surface & augment, if not increase, that said table money. But then, what would i know of such things? 23 yrs. as an inspector of new construction of roadway & bridges for TXDOT. "Inspectors are like morticians, no one want's to have to deal with them, but both keep things from stinking later on."-gilpin 41817
Juan Thank You for all your informative reports. I am up here in Canada and have been following you reports on Oroville Dam. Keep up your great reporting and I watch your others as a pilot also....
Well done again Juan. A small point, ... cavitation is the implosion of water vapour bubbles not air bubbles. Liquid water changes state to vapour because of changes in temperature & pressure (eddies caused by the undulations on the surface of the concrete will facilitate this) then very quickly changes state back again from vapour to liquid. It's the speed of the latter change of state which causes the damage, - it's faster than the speed of sound and the consequential shock wave is the culprit. What you see at the back end of an outboard motor are vapour bubbles not air bubbles. Keep up the good work. Best from Ireland.
Hello White Lily - I just wanted to thank you for these excellent videos which keep us informed on those dam repairs and to thank you for turning me on to the music of Aram Bedrosian. I might never have discovered him if not for you. Keep up the great work.
Very informative. I worked for Kiewit years ago in Boston on the 'big dig'. Good, top shelf outfit. They got their end of it right, at least here in Boston, where they built several structures: Zakim Bridge, Ted Williams Tunnel and extension and several more. If I lived around the dam, I'd be glad Kiewit was doing the work.
Great report, appreciate your technical review of items and informative videos on the Oroville spillway.One very small comment regarding the joints. The first joint that you show is correctly discussed as an expansion joint and the reinforcing steel does not continue through it. The last joint shown near the end of the video appears to be a construction joint, used when the contractor ends that segment of work on a temporary basis (13:34). The last type of joint that I did not see, that they may have used is a contraction joint, or weakened plane joint. This type of joint would be placed after the concrete had been poured and either scribed or sawcut into the concrete to create a weak spot where cracks caused by concrete shrinkage during the curing process would form. This prevents cracks from taking on a random locations and induces a pattern. There is a fairly strong chance that they did not put these in the spillway given the crack patterns shown in the videoKeep up the good work, love your presentations and appreciate the hard work you are doing.
I have no clue to what you just said,lol! What a hell of a noteable college report ,Mr Browne. You left no rock unturned , fantastic , thorough research and explained like a college professor . Please keep that camera rolling ,there will be lots more as the 2017-18 unfold!It will be interesting ! Thanks Mr. Browne.
Great presentation! As a kid fresh out of high school I worked on construction surveys on the intake, transition tube, and powerhouse structures, but was not involved in the dam proper or the spillways. It's interesting to see this presentation on the spillway failure -- basic fundamentals violated. 1. If water can destroy something, it will. This is especially true if hydraulic jump and cavitation are involved, because is that hydraulic jump and cavitation concentrate high forces into small areas. All spillways involve hydraulic jump and cavitation as part of how the energy of falling water is dissipated. 2. Any structure that is intended to block the flow of water needs to be either absolutely impermeable and strong enough to withstand the resulting static forces; or be constructed according to the principles of a "graded filter" to allow leakage water to escape without eroding the filter itself. 3. If a structure requires a foundation, foundation failure leads to the failure of the rest of the structure. (This is most commonly seen in roadways, were potholes develop: the general public thinks that the pavement failed resulting in the pothole, whereas what really happened is the foundation failed resulting in pavement failure. And, since it rains nearly everywhere that roads are built, an engineered roadway must be constructed according to the principles of a "graded filter". ......The basic problems needing to be solved in an engineered roadway are about the same ones that apply to spillway design. ***************** I remember seeing the auxiliary spillway to the north being built and thinking "Gee, I hope no water ever has to go over this thing!" Just a kid out of high school, no knowledge of formal hydraulic engineering principles. But at least I'd played outdoors as a kid and seen what water does to dirt and gravel! Nearly 50 years later, civil engineers started thinking that same thought. The design violated all three of the three basic principles I listed above. ******** Another thing that stands out from my memories of the dam construction is that the contractor McNamara-Fuller management frequently overruled their own experts when it comes to dynamite and to construction cranes. Through shockingly stupid mistakes they destroyed their highline tower on the south abutment intake structure (fortunately nobody seriously injured) , and literally dynamited an enormous conventional crane to the bottom of the intake tube on the north abutment (nobody hurt). Thanks, folks, for a good fogie reminisce. [more edit] Guess how you bond to polyethylene sheet? A. You don't. May as well be a layer of grease. ......This doesn't mean don't use plastic water barriers, but it does mean you have to pay attention to what the structural implications are. [and more] en.wikipedia.org/wiki/Hydraulic_jump en.wikipedia.org/wiki/Teton_Dam Teton dam failure root causes were unsuitable geology (defective foundation) and neglect of the principles of graded filter design. The dam failed while the reservoir was being filled for the first time. As the failure began, they tried to stabilize it by dumping riprap rock on the downstream face where the water was emerging, an utterly useless tactic which illustrates the Bureau engineers' complete ignorance of how dams work. I looked for a good pic or wiki on graded filters but didn't find anything suitable for a quick explanation.
Good ole Huell Howser RIP. I have lived in California all my life and didn't know half of the stuff on his show existed until seeing it. He kept coming up with interesting things and places to profile every week.
Sounds to me like your diagnosis was pretty much on the money! You pointed out most of that for us a while ago. Thanks for the update. Hope you guys enjoyed your vacation and had a good holiday!
Juan- I've watched the majority of your updates since the spillway incident. I'm very impressed by your expertise and passion for this complex issue. Thanks for your focus.
Thanks blanco ! Being an old time Bricklayer from the UK i can tell you that if you have a " Pree stressed concrete lintel " That goes over doors n windows the R bar should always be at the bottom of the { Concrete } lintel ! { Go n get a sponge n bend the ends upwards at each end- It compresses the top n stretches the bottom ! Sorry i wrote this before the end of the vid n you explained the R bar position -- Anyways my 2 pennith post ! Again thanks blanco
Great job Juan. The rebar design they used would only help with perpendicular displacement it had no chance of preventing lateral slippage. Which means holding the slabs from spiking down hill, which is what happened. Even an L-bend at the end would have helped. This analysis makes total sense.
Nice job of explaining this in everyday language, Juan. I've been involved with heavy civil construction projects for over 30 years, and one of my early mentors told me, "there's two types of concrete: concrete that has cracked; and concrete that will crack". It's controlling where the cracking takes place is of extreme importance. I'm very curious how the reinspection and retrofitting of other dam structures and spillways is going to play out over the next few years.
Really like your series on the Oroville Dam. Good content with facts (negates "fake news fanatics"). I would like to help maintain the accuracy of your presentation: your description of cavitation mentions a "bubble of air" created by the water flow. You then say it forms and collapses. It is actually a bubble of vacuum created by turbulence in the water flow which slams shut when the pressure equalizes. The mass of the water acts like a jackhammer when the vacuum bubble slams shut. The activity can eat solid rock, refined steel, even ceramic in the right circumstances.
In the paper edition of the LA Times today, the reporter did complain about the secrecy of the DWR, as well as some analysis of the report was given. The excuse that this was design from 50 yrs ago is just plain weak. Working in construction for than 50 years myself, we built foundations and even driveways to a higher standard than this. What was the cure strength of the concrete? And etc. ....
Very helpful report, nicely done. One note about cavitation. I think the bubbles are not air but water vapor at reduced pressure, where stresses have pulled the water away from itself, creating a rupture in the liquid, shaped like a bubble but full of nothing but vacuum plus water vapor at the temperature and pressure at hand. If there were air in the bubble it wouldn't crush, but with nothing in there but water vapor, the "bubble" can implode destructively.
I continue to be concerned about the spillway control gate structure and it's known column cracks and spalling. It may be inadequately supported by bedrock and has obviously been experiencing stress damage and possible shifting. I expect the upper end of the spillway to be seriously undermined as that has been a primary source water flow underneath the spillway slab. Some of the photographs show gate leakage disappearing through the cracks in the upper spillway just below the control structure. My personal recommendation would be to keep the current spillway operational and begin construction of a new spillway channel diagonally southwestward starting on the current boat ramp parking lot adjacent to the current emergency spillway. Repair the current spillway to be used as the replacement for the current emergency spillway after the new spillway is completed.
You are spot on Robert. So far, I haven't seen any indication the Kleiwet has been contracted to replace it. I hope they will, and repair the top of the SW also, because photos of it prior to the major February cavitation, show a strip of cracked and separating concrete that looks like a Detroit sidewalk. Top to bottom, it needs to be replaced. My feeling is that the entire Oroville system needs to be retired and replaced.
Well as you say Juan, it lasted 50 years and gave Californis bragging rights in national publications of the cheapest water and electricity in the nation. So now the spillway is used up and gets a redo courtesy of someone else...wonderful system. Build a huge water network too big to fail. Build it cheap..let future generations fix it. The American way. Happy trails.
Don't recall the exact words.......Neil Armstrong was asked if he had any trepidations about going to the moon. He replied that they knew the risks. At one point he was awake alone monitoring the systems and stared to look around. He's surrounded by millions of parts that his life depends on and "each one supplied by the lowest bidder"
Juan, a great informative report. As a former construction person it appears that Mr. Bea's analysis is "spot-on". Those aerial views showing the cracking over the drain pipe should have been repaired promptly and the maintenance done on a regular basis. Pay a million dollars for repairs/maintenance now or pay several tens of millions for reconstruction later. A poor mismanagement of funds! With the fast pace of this proposed construction, a lot of qualified engineers and inspectors will be needed on the job site! They'll be some of the most important members of the construction team! ....13
Thanks again, Juan. Hearing your explanations, then seeing the "Herringbone" cracks, I Get it! Those pics of the cracks- are the visual warning of the impending disaster.
Thanks for the Link Juan. Your followers were pretty much on the case from the beginning noting the inconsistencies in re-bar in spacing & cross section & lack of tension reo. It has been a fascinating & scary ride so far.
Another good video, seems like every time i get a lil lost on any of your videos you stop and re-explain the detail I'm missing, like you know and are talking directly to me, thanks for the info.
Juan, thanks for the time you put in making these presentations. I find it very interesting. I look forward to getting new videos from you when available. I'm curious on a 1-10 scale with 10 being the worst how bad would you say they designed the spillway? Nothing lasts forever and the Spillway is 50+ years old correct? If correct how many years do they anticipate the Spillway lasting? Being a native and currently living in Las Vegas I have thought about how Hoover Dam was constructed and how long those design features will currently last by today's standards? Lastly, how many other damn/spillway's were constructed by the company who created the Oroville Spillway? And you mention design standards changing from 50 years ago at construction to currently now which effected the Spillway. My question is why do the design standards matter now verses 50 years ago? because to me water is water it was the same 50 years ago. it hasn't gotten any heavier or dense with time. What am I missing here? Hope that makes sense. I am not an engineer so excuse my ignorance LOL
I found out that the Oroville dam is an 'Earthern Dam' > which means that it's not built on Solid Bedrock! I also found out that the Hoover Dam IS Built on Solid Bedrock, that it is not an earthern dam > so, it is actually a Safer and Stronger Dam+
Devin Henderson The design changes eliminate the cavitation issue, that caused the spillway failure to begin with. They were just to cheap out there to spend the money to add the simple features.
Wow, and again, Wow! Thankful for the disclosed report, but shocked at everything that was found wrong. No surprise the SW failed. A miracle indeed that it was not worse, it so could have been. Thank you again for a wonderful report.
Very good explanation. The spillway might look like just a big slab of concrete to us non-engineers, but there's an awful lot of technical considerations in designing one. I never would have thought about water getting underneath it and what that would do.
Great report, Juan. I have a background in concrete reinforcement (...though more of a draftsman/QS than a Structural Engineer). You described the concepts of reinforced concrete really well for lay people. Well done. Looking forward to your reports in the months ahead as Engineering & Construction continues a never ending battle with Mother Nature and physics.
Hello Juan, at 6:30 about your comment that the herringbone pattern of the drain pipes is a little exagerated, personally I think not, because the drains take the water from underneath the spilway, and dump it very high on the sidewalls, maybe 10 ft. high or more. Plus the additional depth under the floor of the spillway. So, to have enough head for a good flow, they have to dump the water much further downhill than they take it. Hence necessitating a steep herringbone pattern. Thanks from Canada for the videos, they are very interesting.
I wonder how you can add load transfer bars across the concrete slab expansion joints without defeating the action of the expansion joints, at about time mark 8:47 and image page 9 of report.
Slots can be cut into the surface of the slabs and bars inserted in place with the upstream end (or high end) lubricated and then the entire bar is epoxied into place with the appropriate materials. Materials are available that are much stronger than the basic concrete slabs and adhere tenaciously. I have seen instances where a contractor was required to retrofit miles of highway in this manner because the bars were left out during initial construction.
Alright, and maybe there is some kind of "stopping anchor" on the high lubricated end of the transfer bar that doesn't let the joint expand past a maximum limit.
I think if the coefficient of thermal expansion is similar for concrete and steel that this would also create a defeating action on the expansion joints because the bar would be expanding across the slab joint in the opposite direction of the expanding concrete that is closing the joint. And because the bar would need to contract to allow for the closing of the joint due to the expanding concrete, but as you know the bar and concrete don’t do that because they expand and contract together at the same time.
Fascinating report! The thing that was most interesting to me was the seepage into transverse joints higher up on the spillway. Anyone else see that as an issue? If a significant amount of water is getting under the spillway, wouldn't that cause new voids to be created, leading to additional/new collapses in the concrete?
The detail shows show the joints are supposed to be sealed. But obviously the seals deteriorated. Probably way more area on the cracks than the area of the perforations of the clay pipe. The cracks sent more water under the slab than the drainage system could handle.
SkilledMaverick Yes, I saw it and am sure that dam is not safe, and won't be unless it's rebuilt. How bout the seepage in the dam face itself. That is very dire, in my opinion.
Thanks Juan! I certainly hope that the replacement will be built on piles sunk into the bedrock. Relying on the stability of the underlying rock and concrete is not a recommended solution. Build this thing as if it was a freeway overpass! Definitely fill the entire underlying area with concrete, but the important point is that the actual weight is on the pilings. In this way it can also be made earthquake proof. Taking this approach would allow piles to be placed relatively quickly and in between spills. Properly protected (wrapped), these pilings would be unaffected by subsequent spills allowing this work to be done sooner than later.
So what was the ground prep for putting in the spill way? I've seen buildings here in Texas from the 1920's with no ground prep before pour and they all end up with voids full of water. I'm guessing they didn't go near deep enough if they are still dealing with water under the concrete.
Keeping tabs on this disaster by using your YT updates. Thanks for the time and effort devoted. You really make this interesting and provide some good insight.
Great video, I hope this cracked up spillway can hang in there a few more times. I'll follow up on the links and check out the report. Keeping an eye on the river & dam and inflow/outflow data,coming to you from Evacuation Area 1A Oroville, Ca......Have positive thoughts please.
you have identified the slab weakness. The key is how the water washed the soil under the slab. That is what triggered the failure. You are doing a great job.
Really appreciate your balanced, unsensational and well-researched information on the Oroville Dam situation. Thanks for sharing your insights in a beneficial and constructive way. I've learned a lot from your channel on lots of interesting topics. Keep on doing what you do.
I worked for Keiwit back in the stone age. They have some smart people, at least back when I worked for them. They used to have a pretty significant sized field office up here in Washington state. Nice thing about this job, it isn't rocket science. This is pretty standard dirt and concrete work. It's been done before, in much worse conditions. A California summer and fall job. In a beautiful part of the country, with fishing close by. Hmm... Maybe I should give my old contacts a call. I'd be willing to come out of retirement for the right amount of money. LOL!! I would be willing to bet the phones and emails are blazing away at the closest Keiwit office today!!
Well, it appears to that it was rocket science in the 1960s if you want to believe it met standards. It may turn our to be rocket science of a rube goldberg set up depending on how much of the old structure will be kept.
+archerlane That was the part I found suspicious ... did it _really_ meet standards or did it meet "standards" as defined by persons whose "standards" were perhaps ... *_reconfigured._* I could be entirely off base but it just kind of _looks_ that way to me ... based on current analyses, not the least of which is the "in your face" stuff ...
archerlane I wasn't on that job in the 60's. I believe I was building small dams in the creek behind my family home and making Soapbox Derby racers. The old requirements for construction standards were obviously lacking in this case. I believe that searching the old bid documents and inspection records would answer the questions many of us have. But I'm not volunteering for that job. They don't pay enough for me to dig through archives.
Keiwit just finished the new spillway at Folsom Dam. Took about 3 years and was a major undertaking. I've driven by it every week during construction to watch it gradually take shape. Don't think it's been used yet this year despite the heavy rains. So much water has been spilled out the main Dam -- sad that we couldn't store it for the future. Auburn Dam, anyone?
Dug up many broken shattered clay pipes from concrete. The concrete moves more than the clay can handle and they split. Those pipes probably been leaking for 25 years+
Great update Juan, thank you very much. More to this story to come and will they learn from all this...yes but I doubt there will be enough money to go around all the dams which are no doubtably in need of updating.
Thanks on another great pice of news. You make understanding of this catastrophic event easy. Let's hope other dams take notice on what should now be part of proper dam maintenance.
Great report. One nit to pick however. Cavitation is not "air". it is essentially "steam". The negative pressure in the turbulent flow creates enough energy to "evaporate" the liquid. The collapse is essentially the re-condensation of the water vapor.
nice job interesting stuff one comment is that the thickness of the concrete over the drain pipe appears to be more than 6 to 8 inches possibly a foot or more comparing to the thickness of the spillway wall.
Fantastic stuff Mr Browne....you've had me hooked a month ago when I stumbled onto your productions as I am fascinated by these man made structures and their weaknesses with what others warned about in potential failure (s) such as these chain of events played out here...
Juan, thank you so much. I'm going to include some of Dr. Bea's slides from his Root Causes Analysis/Failures Report in my upcoming dam safety training power point presentation. Keep up the great work!
I think Juan said it best when he referred to the spillway as a four lane highway. The systematic designs for highway construction is much different these days then it was back in the 60s. Back in the 80s the Federal Highway Admin started to replace the entire Interstate system with better roadways and concrete design and I think that is when they revamped large building and highway construction codes and design processes. From what I have heard, back in the 50s and 60s, highways and bridges were designed to only last 30 years or so and the Oroville Dam spillway is no exception. Cracks in the spillway were a tale tale sign of needed replacement and that is the true failure of what had occurred, the lack of replacement when it was overdue. One other note, I only know a very little about construction but the few things that I would add is Core Samples to verify the composite of the concrete and to affirm that the concrete was poured correctly meaning that a concrete vibrator was used correctly to remove all the air bubbles / air pockets in the poured concrete for further concrete strength. Nowadays, I believe that federal projects require that the concrete will last 100 years. As for the cost, I would estimate $1 Billion to properly replace both the spillway and emergency spillway and maybe even upgrade the hydroelectric power system. Once all of this is done correctly, it will last 100 years without a problem. Yes, we the people will pay for this as we the people need the dam. In the end, the Oroville dam spillway was not a design failure, it was just the best that we could do at the time. As I always say, there is always room for improvement.
Many thanks for another excellent public information broadcast which we are reading here in the UK. Looking at the drain bell end, surely the bell end should be facing up hill so as to cup the down-flow within the pipe. As it is shown any seepage in the downhill flow would surely blow the pipe joint apart?
Very good report as usual. I saw your drawing at the end showing how the slab should look at the drain pipe. It showed the slab actually thicker at the drain instead of thinner and the pipe surrounded by gravel. That would be a lot of extra digging in solid rock sideways across a steep slope. Easier to grade the rock to bottom of slab level and lay the pipe on top. Design or construction short cuts? Do they have the original drawings? Or did they lose them in the fire at the pool 1 power plant?
Good afternoon Mr. Brown, I love your play-by-play of the Oroville Dam / Spillway situation. I live here in Inglewood, California. suburb of Los Angeles. I have been watching your play-by-play since it began. Keep up the good work. The information has been very informative and educational. One question: Have they made a full inspection of the dam itself?
Wish my grandpa was still alive, I'm sure he would have some interesting insights on this situation. He engineered the Whiskeytown Dam, which is also an earthen dam. Going to work with him as a kid in the early 1960s was the first time I saw a Glory Hole, though I never saw it in operation. I got to see the ghost town of Whiskeytown before it was flooded.
The design of the concrete spillway slabs calls for the load transfer bars to be installed in the slabs near the bottom, but the report says they were placed near the top which is interesting, but maybe is not that important! See bars designed near bottom of slab, bar captioned with "Wrap this end only to prevent bond," PDF page 13, labeled page 6, “Detail A Lateral Expansion Joint,” and bars constructed near top of slab, caption "Load Transfer Bar (as constructed - not shown in diagram)," "Typical Detail Slab Edge Expansion Joint," PDF page 16, labeled page 9).
The intended purpose of those earthenware pipes underneath the spillway was to reduce pore pressure. Pore pressure is the hydraulic pressure of water. It can be immense and can hydraulically force apart pretty much anything. What we can see in at least one of the pictures is that the pipes have been completely surrounded by concrete thus sealing the pipes from being able to allow the migration of water into the pipes and thus they are not able to relieve the pore pressure below the spillway. A better design would have been trenching the pipes into the rock rather than laying the pipes over the rock and surrounding the pipes with the spillway concrete. Better that the pipes are surrounded by porous gravel and the gravel wrapped in geotech fabric. Hindsight though is a wonderful thing.
I'm trying to keep up with Juan, and hate to expose my ignorance, but I am ..... technically challenged. Would really appreciate any info you could give me. - the drains are for what? - and hook into the clay pipes? - not understanding Juan's refs to "herringbone" - how are the pipes arranged under the spillway? - are the expansion joints part of the problem? Thanks.
The clay pipes are governed by the golden rule of drainin water...the fall or downward angle of the pipe to carry off the water was constrained by the thickness of the concrete thus to increase the flow of the water out of the pipes to the side drains the designer angled the pipes down the slope creating head pressure enough to direct the water up the sides and out of the drain openings. It is now obvious that this spillway is like a layer of dominos with tremendous leaks between the slab blocks that are so visible in the wreck of the lower spillway. Also, the designers neglected the forces of friction involved at the flow increased to 137,000cfs which would open up the joints allowing even greater leakage and soil/rotten rock disolving underneath the slab allowing movement in more directions..up, down, sideways. This spillway was so porous it deserves to be called a seive, and the designers collander salesmen.
Thank you sir for the best presentation, can you provide the report (Preliminary root causes analysis of failures of the Oroville dam gated spillway) for me which your showing in this video?
It is nice to see that those of use who have mentioned cavitation in other videos (and been constantly and sometimes rudely shot down) and in previous Juan videos, have been vindicated that, while not the primary cause, cavitation has been a factor in this.
I work construction and I have a pretty good grasp on the civil engineering with respect to drainage and how the work is supposed to be carried out. I seen something strange in the report with respect to the VCP under spillway! Those pipes are supposed to be able to allow water to permeate through into the pipes but they appeared to have poly placed over them greatly reducing their ability to absorb water as they were designed to do. Also the connections didn't appear to be level enough to create a seal at the bell and spigot as the concrete actually in spite of the poly was able to make its way between the bell and spigot connection which makes me think that there was a great deal of deflection at some joints to the point where there may have been significant leakage at joints. I understand the need for a break between the concrete and VCP but why wasn't filter cloth used for this and why was pipe installed with so much deflection?
Juan, Glad you had recent good time with your family on your road trip. Thanks for your many updates. As a photographer who loves your GoPro shots (tho I don't have one), I'm curious about how you go (pretty smoothly) from wide over-your-shoulder to close-in on laptop. Do you have camera mounted on some sort of moveable/hinged gyro arm?
Don't forget to let people know why we use re-bar instead of cable or any other metal. Both iron rebar and concrete heat up and cool at the exact same rate. So one's temperature from freezing or baking in the sun won't cause the other to fail or separate.
Excellent overview. I hope that all the other spillways with the risks outlined in the report are carefuly inspected and repaired before another 'pineapple express' comes through.
Gosh, thanks a lot! You are just such a great resource about the dam. Quite sure we never would have known any of this rather awful construction/upkeep history if not for for Mr. Bea and for you passing it on to us. A public service for sure that may cause consternation in some quarters, but we deserve the truth in forming our opinions. Good job.
Juan, at first I didn't think I would care much about this dam fiasco, considering I live in Michigan. The more I watch your channel updates, I have found myself more and more intrigued. This interest is because of how you are reporting it. Your insight and research is a common sense look at the realization our aged infrastructure in this country is in need of attention. Great job.
we need more people to research about WHY this country has such an aged infrastructure, and who's behind it.
Charlie since you live in Michigan I can assume you have gone to Meijer to buy produce lately. If you have in the winter you will notice that most of the produce you buy comes from California. This dam feeds the aqueducts that supply water to the farms for the produce we buy. That is why this dam is so important nationwide. Without this dam working properly we would lose a good portion of the produce we buy as a nation.
Money is the answer. No one behind it. Where do we spend the money? Most of the Federal budget is spent on Pensions, Health Care, Education, Defense, Welfare, Home Land Security, and Transportation.
One or all needs to be cut to pay for infrastructure upkeep. One less Aircraft carrier maybe? Fewer Teachers? Tough choices.
we have aging infrastructure because those in charge of the budget forgot that everything has a service life ... therefore continuous maintenance is needed or thing fail ...
Charlie Brown I'm in the UK and I've gone well past the boredom stage thanks to Juan. I was border line bored with the news channel reporting when I discovered Juan, now I'm here for the ride!
Mr. Brown, I want to thank you for insightful reporting on the Oroville Damn issue. I caught a very brief mention of this on the national news and out of curiosity searched RUclips for more information, where I found your channel. I found several other channels related to Oroville, but yours is the most captivating, professional and well produced of all of them. I liked your exit music and am really into Aram Bedrosian now. I briefly lived in southern CA for a short period and have visited North CA several times, but am now on the south east coast. Even though I am far away, this topic captivates me, as I am a civil structures buff (love to visit Damns and such all over the world). Please continue this series through completion of all the repairs.
Myself as a Commercial and Industrial Electrician for 30 years, you absolutely nailed it with this report! The evolution of building standards have come a long way since 1965... you can really see the deficiency in the original build design from that era compared to what the newer Code Standards of today.
Great job Mr. Brown :-) I have been following your work since your first video... looks like a second career as a consultant... lol
Great job as always Juan. As a civil engineer, I enjoy all the content, including technical data you provide on the Oroville issues. Educational, and matter of fact.
The new media is here, and we are never going back. No more ignoring vital information. No more lies. My deepest gratitude Juan!
Great explanation, Juan, and many thanks for taking the time to do so! That independent study is quite the eye-opener...wow...
Methinks that the vegetation growing near the spillway was an indicator of how much water was leaking from under the spillway.. Opportunistic seeds take hold where moisture is present, after all.
Wow, there was so many warning signs. California officials have some serious explaining to do. I can't wait for a full length documentary about the Oroville dam spillway failure. A lot of awesome hd footage has been collected, hopefully whoever produces the first major documentary uses Juan Brown as one of their main sources and consultant.
I would also like to see more investigation about the cavitation that occurred on the spillway. Cavitation is literally one of the most destructive forces of nature. No material is safe from the energy release of the collapsing bubbles. Not even tungsten carbide or diamond. The only way to stop the destruction is to design a way to keep the low pressure bubbles from ever forming . I am interested to see how the new modern spillway design will be able prevent cavitation
For the record cavitation is not air bubbles, that would be aeration. Cavitation bubbles are the vapor form of the liquid in question, in this case steam. A low pressure zone causes boiling and then the vapor bubbles collapse back into liquid. The collapse causes a shockwave that causes the damage.
Daniel Armstrong
The kinetics low pressure make literally the concrete boil ...
That's it .
Even the tiniest bubble become blowing material ...
It happens on steel made ...
Daniel Armstrong good point..isn't that gas mostly...'air'?
blancolirio well technically cavitation is water in a gaseous form.. But for all purposes described it is air...
No, there is no air in cavitation. As Mike Cowen points out, adding air can prevent cavitation. Cavation bubbles can kind of be thought of as vacuum bubbles. They are not actually a vacuum because, as Daniel Armstrong said, they are filled with water vapor. But, if the water temp is 60 F, then the pressure in the cavitation bubbles is about 0.07 psi. While not a vacuum, that's a fairly low pressure.
+blancolirio
Not only, on fluids pump "steel made" could be the fluid itself turn in gazes phases ...
There is not that much "air" in gravels concrete like builders try their best to eliminate it, nor in metals alloys ...
Use ore water pump and it would be the same ...
It's a kinetic energy phenomena which have no "regards" to the raw material used ...
No wonder it's the same phenomena astronoms called black holes ...
It's kinetics ...
What that the point ?
You naughty brained Damn shaker !
Juan, thanks for your excellent presentations. Incidentally, cavitation isn't air bubbles. It is caused by low pressure, a vacuum, causing the water to vaporize, or boil. The bubbles are water vapor, not air. You are correct though in that when the bubbles collapse they cause a pressure spike that can damage, concrete, boat propellers and powerhouse turbines.
My dad was a structural civil engineer for South Carolina Electric and Gas and I grew up going to jobs with dad and he'd explain what they were doing and why. Orville Dam is an example why dad always over engineered his jobs. He said he never wanted a structural failure to come back on him. You did an excellent job of explaining the independent report. Dad would have approved.
Thank's for the Stellar Transparency Juan.
1:55 Me too! 6:55 weakened planes. 8:40 no select gravel below said pipe for support cradling. Even you're home's City water meters have @ least 4" below & outside it's edges to insure water junction support.
-Bet they don't utilize the same round aggregate sub-base fill as before.
-Change Orders needed for the original plans are known to most bidders & affords them to leave money on the table in order to win the lowest bid.
-These logically Persuasive future Change Orders eventually surface & augment, if not increase, that said table money. But then, what would i know of such things? 23 yrs. as an inspector of new construction of roadway & bridges for TXDOT.
"Inspectors are like morticians, no one want's to have to deal with them, but both keep things from stinking later on."-gilpin 41817
Juan Thank You for all your informative reports. I am up here in Canada and have been following you reports on Oroville Dam. Keep up your great reporting and I watch your others as a pilot also....
Well done again Juan. A small point, ... cavitation is the implosion of water vapour bubbles not air bubbles. Liquid water changes state to vapour because of changes in temperature & pressure (eddies caused by the undulations on the surface of the concrete will facilitate this) then very quickly changes state back again from vapour to liquid. It's the speed of the latter change of state which causes the damage, - it's faster than the speed of sound and the consequential shock wave is the culprit. What you see at the back end of an outboard motor are vapour bubbles not air bubbles. Keep up the good work. Best from Ireland.
Hello White Lily - I just wanted to thank you for these excellent videos which keep us informed on those dam repairs and to thank you for turning me on to the music of Aram Bedrosian. I might never have discovered him if not for you. Keep up the great work.
Very informative. I worked for Kiewit years ago in Boston on the 'big dig'. Good, top shelf outfit. They got their end of it right, at least here in Boston, where they built several structures: Zakim Bridge, Ted Williams Tunnel and extension and several more.
If I lived around the dam, I'd be glad Kiewit was doing the work.
Great report, appreciate your technical review of items and informative videos on the Oroville spillway.One very small comment regarding the joints. The first joint that you show is correctly discussed as an expansion joint and the reinforcing steel does not continue through it. The last joint shown near the end of the video appears to be a construction joint, used when the contractor ends that segment of work on a temporary basis (13:34). The last type of joint that I did not see, that they may have used is a contraction joint, or weakened plane joint. This type of joint would be placed after the concrete had been poured and either scribed or sawcut into the concrete to create a weak spot where cracks caused by concrete shrinkage during the curing process would form. This prevents cracks from taking on a random locations and induces a pattern. There is a fairly strong chance that they did not put these in the spillway given the crack patterns shown in the videoKeep up the good work, love your presentations and appreciate the hard work you are doing.
I have no clue to what you just said,lol! What a hell of a noteable college report ,Mr Browne. You left no rock unturned , fantastic , thorough research and explained like a college professor . Please keep that camera rolling ,there will be lots more as the 2017-18 unfold!It will be interesting ! Thanks Mr. Browne.
Great presentation! As a kid fresh out of high school I worked on construction surveys on the intake, transition tube, and powerhouse structures, but was not involved in the dam proper or the spillways.
It's interesting to see this presentation on the spillway failure -- basic fundamentals violated.
1. If water can destroy something, it will. This is especially true if hydraulic jump and cavitation are involved, because is that hydraulic jump and cavitation concentrate high forces into small areas. All spillways involve hydraulic jump and cavitation as part of how the energy of falling water is dissipated.
2. Any structure that is intended to block the flow of water needs to be either absolutely impermeable and strong enough to withstand the resulting static forces; or be constructed according to the principles of a "graded filter" to allow leakage water to escape without eroding the filter itself.
3. If a structure requires a foundation, foundation failure leads to the failure of the rest of the structure. (This is most commonly seen in roadways, were potholes develop: the general public thinks that the pavement failed resulting in the pothole, whereas what really happened is the foundation failed resulting in pavement failure. And, since it rains nearly everywhere that roads are built, an engineered roadway must be constructed according to the principles of a "graded filter". ......The basic problems needing to be solved in an engineered roadway are about the same ones that apply to spillway design.
*****************
I remember seeing the auxiliary spillway to the north being built and thinking "Gee, I hope no water ever has to go over this thing!" Just a kid out of high school, no knowledge of formal hydraulic engineering principles. But at least I'd played outdoors as a kid and seen what water does to dirt and gravel! Nearly 50 years later, civil engineers started thinking that same thought. The design violated all three of the three basic principles I listed above.
********
Another thing that stands out from my memories of the dam construction is that the contractor McNamara-Fuller management frequently overruled their own experts when it comes to dynamite and to construction cranes. Through shockingly stupid mistakes they destroyed their highline tower on the south abutment intake structure (fortunately nobody seriously injured) , and literally dynamited an enormous conventional crane to the bottom of the intake tube on the north abutment (nobody hurt).
Thanks, folks, for a good fogie reminisce.
[more edit] Guess how you bond to polyethylene sheet? A. You don't. May as well be a layer of grease. ......This doesn't mean don't use plastic water barriers, but it does mean you have to pay attention to what the structural implications are.
[and more] en.wikipedia.org/wiki/Hydraulic_jump
en.wikipedia.org/wiki/Teton_Dam Teton dam failure root causes were unsuitable geology (defective foundation) and neglect of the principles of graded filter design. The dam failed while the reservoir was being filled for the first time. As the failure began, they tried to stabilize it by dumping riprap rock on the downstream face where the water was emerging, an utterly useless tactic which illustrates the Bureau engineers' complete ignorance of how dams work.
I looked for a good pic or wiki on graded filters but didn't find anything suitable for a quick explanation.
No hype , no sensationalism, just reporting what you have found. Thank you. Perhaps you should be a reporter
You're California's new Huell Howser. Keep up the good work...
that's aMAYYzing!!
Huell would have just kissed the DWR's ass, he wasn't a investigator, just a parrot.
Good ole Huell Howser RIP. I have lived in California all my life and didn't know half of the stuff on his show existed until seeing it. He kept coming up with interesting things and places to profile every week.
Actually Huell would have spent 20 minutes talking about Juan's rain gauge.
..."you mean to tell me..." lol
Makes you wonder what other parts of the dam might be inadequate in design, construction and maintenance. I imagine time will tell.
Sounds to me like your diagnosis was pretty much on the money! You pointed out most of that for us a while ago. Thanks for the update. Hope you guys enjoyed your vacation and had a good holiday!
Juan- I've watched the majority of your updates since the spillway incident. I'm very impressed by your expertise and passion for this complex issue. Thanks for your focus.
Thanks blanco !
Being an old time Bricklayer from the UK i can tell you that if you have a " Pree stressed concrete lintel " That goes over doors n windows the R bar should always be at the bottom of the { Concrete } lintel ! { Go n get a sponge n bend the ends upwards at each end- It compresses the top n stretches the bottom !
Sorry i wrote this before the end of the vid n you explained the R bar position -- Anyways my 2 pennith post ! Again thanks blanco
Great job Juan. The rebar design they used would only help with perpendicular displacement it had no chance of preventing lateral slippage. Which means holding the slabs from spiking down hill, which is what happened. Even an L-bend at the end would have helped. This analysis makes total sense.
Thank you Juan! You're doing a better job of covering this than our local media.
Nice job of explaining this in everyday language, Juan. I've been involved with heavy civil construction projects for over 30 years, and one of my early mentors told me, "there's two types of concrete: concrete that has cracked; and concrete that will crack". It's controlling where the cracking takes place is of extreme importance. I'm very curious how the reinspection and retrofitting of other dam structures and spillways is going to play out over the next few years.
Really like your series on the Oroville Dam. Good content with facts (negates "fake news fanatics"). I would like to help maintain the accuracy of your presentation: your description of cavitation mentions a "bubble of air" created by the water flow. You then say it forms and collapses. It is actually a bubble of vacuum created by turbulence in the water flow which slams shut when the pressure equalizes. The mass of the water acts like a jackhammer when the vacuum bubble slams shut. The activity can eat solid rock, refined steel, even ceramic in the right circumstances.
In the paper edition of the LA Times today, the reporter did complain about the secrecy of the DWR, as well as some analysis of the report was given. The excuse that this was design from 50 yrs ago is just plain weak. Working in construction for than 50 years myself, we built foundations and even driveways to a higher standard than this. What was the cure strength of the concrete? And etc. ....
Very helpful report, nicely done. One note about cavitation. I think the bubbles are not air but water vapor at reduced pressure, where stresses have pulled the water away from itself, creating a rupture in the liquid, shaped like a bubble but full of nothing but vacuum plus water vapor at the temperature and pressure at hand. If there were air in the bubble it wouldn't crush, but with nothing in there but water vapor, the "bubble" can implode destructively.
I continue to be concerned about the spillway control gate structure and it's known column cracks and spalling. It may be inadequately supported by bedrock and has obviously been experiencing stress damage and possible shifting. I expect the upper end of the spillway to be seriously undermined as that has been a primary source water flow underneath the spillway slab. Some of the photographs show gate leakage disappearing through the cracks in the upper spillway just below the control structure.
My personal recommendation would be to keep the current spillway operational and begin construction of a new spillway channel diagonally southwestward starting on the current boat ramp parking lot adjacent to the current emergency spillway. Repair the current spillway to be used as the replacement for the current emergency spillway after the new spillway is completed.
You are spot on Robert. So far, I haven't seen any indication the Kleiwet has been contracted to replace it. I hope they will, and repair the top of the SW also, because photos of it prior to the major February cavitation, show a strip of cracked and separating concrete that looks like a Detroit sidewalk. Top to bottom, it needs to be replaced. My feeling is that the entire Oroville system needs to be retired and replaced.
Well as you say Juan, it lasted 50 years and gave Californis bragging rights in national publications of the cheapest water and electricity in the nation. So now the spillway is used up and gets a redo courtesy of someone else...wonderful system. Build a huge water network too big to fail. Build it cheap..let future generations fix it. The American way. Happy trails.
Evert.... its called ''Award the job to the lowest bidder''.
Don't recall the exact words.......Neil Armstrong was asked if he had any trepidations about going to the moon. He replied that they knew the risks. At one point he was awake alone monitoring the systems and stared to look around. He's surrounded by millions of parts that his life depends on and "each one supplied by the lowest bidder"
Juan, a great informative report. As a former construction person it appears that Mr. Bea's analysis is "spot-on". Those aerial views showing the cracking over the drain pipe should have been repaired promptly and the maintenance done on a regular basis. Pay a million dollars for repairs/maintenance now or pay several tens of millions for reconstruction later. A poor mismanagement of funds!
With the fast pace of this proposed construction, a lot of qualified engineers and inspectors will be needed on the job site! They'll be some of the most important members of the construction team!
....13
Nice clear explanation of the failure...for those of us that can't or won't read the long technical report.
Thanks again, Juan. Hearing your explanations, then seeing the "Herringbone" cracks, I Get it! Those pics of the cracks- are the visual warning of the impending disaster.
Great report Juan. Keep up the good work.
Thanks for the Link Juan. Your followers were pretty much on the case from the beginning noting the inconsistencies in re-bar in spacing & cross section & lack of tension reo. It has been a fascinating & scary ride so far.
Another good video, seems like every time i get a lil lost on any of your videos you stop and re-explain the detail I'm missing, like you know and are talking directly to me, thanks for the info.
Juan, thanks for the time you put in making these presentations. I find it very interesting. I look forward to getting new videos from you when available.
I'm curious on a 1-10 scale with 10 being the worst how bad would you say they designed the spillway? Nothing lasts forever and the Spillway is 50+ years old correct? If correct how many years do they anticipate the Spillway lasting?
Being a native and currently living in Las Vegas I have thought about how Hoover Dam was constructed and how long those design features will currently last by today's standards? Lastly, how many other damn/spillway's were constructed by the company who created the Oroville Spillway?
And you mention design standards changing from 50 years ago at construction to currently now which effected the Spillway. My question is why do the design standards matter now verses 50 years ago? because to me water is water it was the same 50 years ago. it hasn't gotten any heavier or dense with time. What am I missing here? Hope that makes sense. I am not an engineer so excuse my ignorance LOL
I found out that the Oroville dam is an 'Earthern Dam' > which means that it's not built on Solid Bedrock! I also found out that the Hoover Dam IS Built on Solid Bedrock, that it is not an earthern dam > so, it is actually a Safer and Stronger Dam+
Devin Henderson---1-10, it's an 8, imo.
3.5 or 4
I would give it a 7 for the original build but with the caveat that they let it deteriorate to a 10+.
Devin Henderson The design changes eliminate the cavitation issue, that caused the spillway failure to begin with.
They were just to cheap out there to spend the money to add the simple features.
As usual, great reporting! Thanks Juan!
Wow, and again, Wow! Thankful for the disclosed report, but shocked at everything that was found wrong. No surprise the SW failed. A miracle indeed that it was not worse, it so could have been.
Thank you again for a wonderful report.
Very good explanation. The spillway might look like just a big slab of concrete to us non-engineers, but there's an awful lot of technical considerations in designing one. I never would have thought about water getting underneath it and what that would do.
Great report, Juan. I have a background in concrete reinforcement (...though more of a draftsman/QS than a Structural Engineer). You described the concepts of reinforced concrete really well for lay people. Well done. Looking forward to your reports in the months ahead as Engineering & Construction continues a never ending battle with Mother Nature and physics.
Hello Juan, at 6:30 about your comment that the herringbone pattern of the drain pipes is a little exagerated, personally I think not, because the drains take the water from underneath the spilway, and dump it very high on the sidewalls, maybe 10 ft. high or more. Plus the additional depth under the floor of the spillway. So, to have enough head for a good flow, they have to dump the water much further downhill than they take it. Hence necessitating a steep herringbone pattern.
Thanks from Canada for the videos, they are very interesting.
I wonder how you can add load transfer bars across the concrete slab expansion joints without defeating the action of the expansion joints, at about time mark 8:47 and image page 9 of report.
yes!
Slots can be cut into the surface of the slabs and bars inserted in place with the upstream end (or high end) lubricated and then the entire bar is epoxied into place with the appropriate materials. Materials are available that are much stronger than the basic concrete slabs and adhere tenaciously. I have seen instances where a contractor was required to retrofit miles of highway in this manner because the bars were left out during initial construction.
The coefficient of thermal expansion is similar for concrete and steel.
Alright, and maybe there is some kind of "stopping anchor" on the high lubricated end of the transfer bar that doesn't let the joint expand past a maximum limit.
I think if the coefficient of thermal expansion is similar for concrete and steel that this would also create a defeating action on the expansion joints because the bar would be expanding across the slab joint in the opposite direction of the expanding concrete that is closing the joint. And because the bar would need to contract to allow for the closing of the joint due to the expanding concrete, but as you know the bar and concrete don’t do that because they expand and contract together at the same time.
Fascinating report! The thing that was most interesting to me was the seepage into transverse joints higher up on the spillway. Anyone else see that as an issue? If a significant amount of water is getting under the spillway, wouldn't that cause new voids to be created, leading to additional/new collapses in the concrete?
The detail shows show the joints are supposed to be sealed. But obviously the seals deteriorated. Probably way more area on the cracks than the area of the perforations of the clay pipe. The cracks sent more water under the slab than the drainage system could handle.
SkilledMaverick
Yes, I saw it and am sure that dam is not safe, and won't be unless it's rebuilt. How bout the seepage in the dam face itself. That is very dire, in my opinion.
Once again you put out some great info. I wish my Dad was still alive to see this! He helped build the spillway.
Thanks, Juan. It's very interesting to start seeing some of the 'cause & effect' diagrams and pictures of why there was failure.
Thank you Juan, you explain things so clearly without the fear mongering of other channels.
Thanks Juan! I certainly hope that the replacement will be built on piles sunk into the bedrock. Relying on the stability of the underlying rock and concrete is not a recommended solution. Build this thing as if it was a freeway overpass!
Definitely fill the entire underlying area with concrete, but the important point is that the actual weight is on the pilings. In this way it can also be made earthquake proof.
Taking this approach would allow piles to be placed relatively quickly and in between spills. Properly protected (wrapped), these pilings would be unaffected by subsequent spills allowing this work to be done sooner than later.
and once again, new media kicks the shit out of old media in getting useful, accurate information out to the public.
Nice job.
So what was the ground prep for putting in the spill way? I've seen buildings here in Texas from the 1920's with no ground prep before pour and they all end up with voids full of water. I'm guessing they didn't go near deep enough if they are still dealing with water under the concrete.
Keeping tabs on this disaster by using your YT updates. Thanks for the time and effort devoted. You really make this interesting and provide some good insight.
I love your reports, very professional, based on facts, and not on chats !!!! THx
Great video, I hope this cracked up spillway can hang in there a few more times. I'll follow up on the links and check out the report. Keeping an eye on the river & dam and inflow/outflow data,coming to you from Evacuation Area 1A Oroville, Ca......Have positive thoughts please.
you have identified the slab weakness. The key is how the water washed the soil under the slab. That is what triggered the failure. You are doing a great job.
Yes!
Really appreciate your balanced, unsensational and well-researched information on the Oroville Dam situation. Thanks for sharing your insights in a beneficial and constructive way. I've learned a lot from your channel on lots of interesting topics. Keep on doing what you do.
I worked for Keiwit back in the stone age. They have some smart people, at least back when I worked for them. They used to have a pretty significant sized field office up here in Washington state.
Nice thing about this job, it isn't rocket science. This is pretty standard dirt and concrete work. It's been done before, in much worse conditions. A California summer and fall job. In a beautiful part of the country, with fishing close by. Hmm... Maybe I should give my old contacts a call. I'd be willing to come out of retirement for the right amount of money. LOL!! I would be willing to bet the phones and emails are blazing away at the closest Keiwit office today!!
Well,
it appears to that it was rocket science in the 1960s if you want to believe it met standards. It may turn our to be rocket science of a rube goldberg set up depending on how much of the old structure will be kept.
+archerlane
That was the part I found suspicious ... did it _really_ meet standards or did it meet "standards" as defined by persons whose "standards" were perhaps ... *_reconfigured._* I could be entirely off base but it just kind of _looks_ that way to me ... based on current analyses, not the least of which is the "in your face" stuff ...
archerlane I wasn't on that job in the 60's. I believe I was building small dams in the creek behind my family home and making Soapbox Derby racers. The old requirements for construction standards were obviously lacking in this case. I believe that searching the old bid documents and inspection records would answer the questions many of us have. But I'm not volunteering for that job. They don't pay enough for me to dig through archives.
archerlane: That's the trouble with the past, it's always a different country.
Keiwit just finished the new spillway at Folsom Dam. Took about 3 years and was a major undertaking. I've driven by it every week during construction to watch it gradually take shape. Don't think it's been used yet this year despite the heavy rains. So much water has been spilled out the main Dam -- sad that we couldn't store it for the future. Auburn Dam, anyone?
Dug up many broken shattered clay pipes from concrete. The concrete moves more than the clay can handle and they split. Those pipes probably been leaking for 25 years+
Great update Juan, thank you very much. More to this story to come and will they learn from all this...yes but I doubt there will be enough money to go around all the dams which are no doubtably in need of updating.
Thanks on another great pice of news. You make understanding of this catastrophic event easy. Let's hope other dams take notice on what should now be part of proper dam maintenance.
Great report. One nit to pick however. Cavitation is not "air". it is essentially "steam". The negative pressure in the turbulent flow creates enough energy to "evaporate" the liquid. The collapse is essentially the re-condensation of the water vapor.
the "anchor bar" should point the opposite way you would think??? is it pointing up toward the top or down?
Thank you, Juan. You are my go-to guy for news on Oroville dam.
You get a gold star ⭐️ for the day Juan.
Thank you for your reports. Living in New England we have not gotten much information on this tragedy that could get so much worse.
Great stuff Juan. Thanks.
nice job interesting stuff one comment is that the thickness of the concrete over the drain pipe appears to be more than 6 to 8 inches possibly a foot or more comparing to the thickness of the spillway wall.
Fantastic stuff Mr Browne....you've had me hooked a month ago when I stumbled onto your productions as I am fascinated by these man made structures and their weaknesses with what others warned about in potential failure (s) such as these chain of events played out here...
Juan, thank you so much. I'm going to include some of Dr. Bea's slides from his Root Causes Analysis/Failures Report in my upcoming dam safety training power point presentation. Keep up the great work!
Of course, I stay tune ! ... many thanks for the clarity of your explanations.
I think Juan said it best when he referred to the spillway as a four lane highway. The systematic designs for highway construction is much different these days then it was back in the 60s. Back in the 80s the Federal Highway Admin started to replace the entire Interstate system with better roadways and concrete design and I think that is when they revamped large building and highway construction codes and design processes. From what I have heard, back in the 50s and 60s, highways and bridges were designed to only last 30 years or so and the Oroville Dam spillway is no exception.
Cracks in the spillway were a tale tale sign of needed replacement and that is the true failure of what had occurred, the lack of replacement when it was overdue. One other note, I only know a very little about construction but the few things that I would add is Core Samples to verify the composite of the concrete and to affirm that the concrete was poured correctly meaning that a concrete vibrator was used correctly to remove all the air bubbles / air pockets in the poured concrete for further concrete strength. Nowadays, I believe that federal projects require that the concrete will last 100 years.
As for the cost, I would estimate $1 Billion to properly replace both the spillway and emergency spillway and maybe even upgrade the hydroelectric power system. Once all of this is done correctly, it will last 100 years without a problem. Yes, we the people will pay for this as we the people need the dam. In the end, the Oroville dam spillway was not a design failure, it was just the best that we could do at the time. As I always say, there is always room for improvement.
Many thanks for another excellent public information broadcast which we are reading here in the UK. Looking at the drain bell end, surely the bell end should be facing up hill so as to cup the down-flow within the pipe. As it is shown any seepage in the downhill flow would surely blow the pipe joint apart?
Very good report as usual. I saw your drawing at the end showing how the slab should look at the drain pipe. It showed the slab actually thicker at the drain instead of thinner and the pipe surrounded by gravel. That would be a lot of extra digging in solid rock sideways across a steep slope. Easier to grade the rock to bottom of slab level and lay the pipe on top. Design or construction short cuts? Do they have the original drawings? Or did they lose them in the fire at the pool 1 power plant?
Fantastic reporting and presentation of the available information! :)
Good afternoon Mr. Brown, I love your play-by-play of the Oroville Dam / Spillway situation. I live here in Inglewood, California. suburb of Los Angeles. I have been watching your play-by-play since it began. Keep up the good work. The information has been very informative and educational. One question: Have they made a full inspection of the dam itself?
Thank you Juan, for consistently putting things in layman's terms for us.
Wish my grandpa was still alive, I'm sure he would have some interesting insights on this situation. He engineered the Whiskeytown Dam, which is also an earthen dam. Going to work with him as a kid in the early 1960s was the first time I saw a Glory Hole, though I never saw it in operation. I got to see the ghost town of Whiskeytown before it was flooded.
The design of the concrete spillway slabs calls for the load transfer bars to be installed in the slabs near the bottom, but the report says they were placed near the top which is interesting, but maybe is not that important! See bars designed near bottom of slab, bar captioned with "Wrap this end only to prevent bond," PDF page 13, labeled page 6, “Detail A Lateral Expansion Joint,” and bars constructed near top of slab, caption "Load Transfer Bar (as constructed - not shown in diagram)," "Typical Detail Slab Edge Expansion Joint," PDF page 16, labeled page 9).
OH ! I see the problem. They lined the spillway with "Saran Wrap". Now I understand. Great! Good job.
Ouch.
Thanks for keeping us informed. Not seeing much in my Google News feed.....
The intended purpose of those earthenware pipes underneath the spillway was to reduce pore pressure. Pore pressure is the hydraulic pressure of water. It can be immense and can hydraulically force apart pretty much anything. What we can see in at least one of the pictures is that the pipes have been completely surrounded by concrete thus sealing the pipes from being able to allow the migration of water into the pipes and thus they are not able to relieve the pore pressure below the spillway. A better design would have been trenching the pipes into the rock rather than laying the pipes over the rock and surrounding the pipes with the spillway concrete. Better that the pipes are surrounded by porous gravel and the gravel wrapped in geotech fabric. Hindsight though is a wonderful thing.
I'm trying to keep up with Juan, and hate to expose my ignorance, but I am ..... technically challenged. Would really appreciate any info you could give me. - the drains are for what? - and hook into the clay pipes? - not understanding Juan's refs to "herringbone" - how are the pipes arranged under the spillway? - are the expansion joints part of the problem? Thanks.
The clay pipes are governed by the golden rule of drainin water...the fall or downward angle of the pipe to carry off the water was constrained by the thickness of the concrete thus to increase the flow of the water out of the pipes to the side drains the designer angled the pipes down the slope creating head pressure enough to direct the water up the sides and out of the drain openings. It is now obvious that this spillway is like a layer of dominos with tremendous leaks between the slab blocks that are so visible in the wreck of the lower spillway. Also, the designers neglected the forces of friction involved at the flow increased to 137,000cfs which would open up the joints allowing even greater leakage and soil/rotten rock disolving underneath the slab allowing movement in more directions..up, down, sideways. This spillway was so porous it deserves to be called a seive, and the designers collander salesmen.
Once again I was captivated by your presentation.
That independent Failure Analysis Report is very good. !! I hope the DWR will Live and learn from professionals and the mistakes will be corrected.
Thank you sir for the best presentation, can you provide the report (Preliminary root causes analysis of failures of the Oroville dam gated spillway) for me which your showing in this video?
It is nice to see that those of use who have mentioned cavitation in other videos (and been constantly and sometimes rudely shot down) and in previous Juan videos, have been vindicated that, while not the primary cause, cavitation has been a factor in this.
I work construction and I have a pretty good grasp on the civil engineering with respect to drainage and how the work is supposed to be carried out. I seen something strange in the report with respect to the VCP under spillway! Those pipes are supposed to be able to allow water to permeate through into the pipes but they appeared to have poly placed over them greatly reducing their ability to absorb water as they were designed to do. Also the connections didn't appear to be level enough to create a seal at the bell and spigot as the concrete actually in spite of the poly was able to make its way between the bell and spigot connection which makes me think that there was a great deal of deflection at some joints to the point where there may have been significant leakage at joints. I understand the need for a break between the concrete and VCP but why wasn't filter cloth used for this and why was pipe installed with so much deflection?
Nice to know the rest of the story. Many thanks Juan!
So the bell end is right up against the crack. Got it.
2 points in the report say continuous steel, meaning the rebar both in the top layer and lack of second layer.
Juan,
Glad you had recent good time with your family on your road trip. Thanks for your many updates. As a photographer who loves your GoPro shots (tho I don't have one), I'm curious about how you go (pretty smoothly) from wide over-your-shoulder to close-in on laptop. Do you have camera mounted on some sort of moveable/hinged gyro arm?
Not today...this was just hand held. I do have a 'Karma Grip' gyro stabilizer which I recently acquired, but has audio issues.
Don't forget to let people know why we use re-bar instead of cable or any other metal. Both iron rebar and concrete heat up and cool at the exact same rate. So one's temperature from freezing or baking in the sun won't cause the other to fail or separate.
Excellent overview. I hope that all the other spillways with the risks outlined in the report are carefuly inspected and repaired before another 'pineapple express' comes through.
Independent review is essential, I thank you for staying on this subject. Have been watching this whole thing unfold with awe for the mistakes made.
Well presented! What is the prognosis?
Another great investigative report. You put the mainstream media to shame. Thank you for your dedication and hard work exposing the truth sir.
I see loads of others trying to follow your blog but for sure you are the best, keep it up. Good reporting full stop.
Gosh, thanks a lot! You are just such a great resource about the dam. Quite sure we never would have known any of this rather awful construction/upkeep history if not for for Mr. Bea and for you passing it on to us. A public service for sure that may cause consternation in some quarters, but we deserve the truth in forming our opinions. Good job.
Juan.... My understanding of cavitation is the energy of a negative pressure bubble it collapses. Does that explanation work?