No conspiracy theories please. I believe this is mostly a case of "stuff happens". Nobody died or got seriously injured and that is good. But I bet the price tag approaches a billion dollars. They shut off the water yesterday since the lake is low enough. I wonder how you all would go about digging out this pile of rock. From a distance it looks like a pile of washed gravel. But there are a few shots with a Cat in it that shows there are lots of these blue rocks about the size of a small car. I saw in another place they had built a road out onto the pile of dirt from the downstream side. Presumably to make it easier for the less nimble equipment to get farther out there. They have barges floating on both sides and even a tug boat. I don't know how they got the tug boat down there. This is a pretty steep canyon with not great roads. I guess the power plant must have a pretty good road. How would you go about cleaning this channel? Start pushing to the south side where the roads are and haul it off one dump truck at a time? What about getting some water back in the channel? Sounds like they want to start flowing several thousand CFS as early as Thursday.
There is a lot of material to get placed back. The equiptment looks like matchbox toys.
Long distance shot of rock trucks. I guess they are just going to stock pile this stuff on this less steep hillside. Maybe they have plans to use it for the thousands of yards of concrete they will be making this summer.
Thanks for sharing Birkin , those videos give some of the best footage I've seen yet . Not sure how the concrete spillway was constructed , some precast / tilt up ? I see allot of square edges & corners left around the floor & walls . Not seeing much rebar hanging out around the damage ??? I would think a project like this would have used allot of rebar in the concrete & pins between section pours /cold joints ?
I saw some close up pictures and there was plenty of rebar in it. Also some real long bolts that used to go into the rock from the walls down. Can't find where it was I got the pictures though. The rock bolts were hanging in midair 20 or 50 feet away from the nearest rock. A lot of crummy rock in this area. They laid that structure over the crummy and the good. They did not expect this to happen. They expected it to stay inside the channel. There is a lot of rebar but it sort of disappears with the scale of this thing like everything else. I'm pretty sure it was all cast in place.
The good news in the paper I was just reading that they got some biologist type people who are running up and down the now dry riverbank and saving any poor fishes that got caught in little pools.
When the BoR tried to top off Lake Powell in 1983, there was an unexpected snow dump in May that caused all the drainages flowing into it to flood. The extra flow of water resulted in the opening of the spillway tube to prevent water going over the dam. The resulting cavitation damage of 100 tonnes/sec. of water flowing over 100+mph was incredible. Several videos documented the event and subsequent repairs in 83-84. Lessons learned included putting an air cushion under the flowing water to slow down cavitation damage and leaving room in the reservoir for the unexpected.
The interesting thing is that Oroville has seen many of those type floods over this spillway since the early 1970s and many since the Powell event in 1983 which I am sure made them recheck the facility. When it broke up this time it was way below what it has been tested with in the past. I just hope the short inspection they got in there and did at the beginning of this whole thing, plus the records allows them to determine a cause because all evidence has been washed away and ground to powder at this point.
Here is a video i stumbled on this morning.
That is the best one yet. Must be brand new because I see more activity in that one than any of the others. Trying to figure out where the long reach excavator on the barge has put the rock it dug out of that hole. I guess if they get the channel opened up they can run the powerhouse and then work on the rest of the rock pile into summer rather than moving a whole fleet of machines in there to do it in a short time.
They knew it needed upgrading over ten years ago, but complacency and money-grubbing vetoed that. Everybody figured with the drought it was no worry and if it did start to rain it would take years to fill the reservoir, right? Right fellas, nothing to worry about huh? Hello? Hmmm... people SHOULD get fired or recalled over this, but no, anyone responsible will get promoted/reassigned/retired. And now we know that the 50 year old emergency spill wall was only designed to give some people enough time to run like hell to higher ground before the whole mess breached catastrophically. Truly the term "Emergency" was aptly applied, a bit like putting a tube of sunscreen in a nuclear blast survival kit.
Looks like the long reach is loading the barge to it's left. I don't know what they are gonna do with it after that, b/c that's the upriver side of the rock. They had a couple long reaches trying to deslit around the powerhouse before things went completely sideways.
I worked with some guys dredging here in town this past summer, and a few summers ago also after some flooding. They would load the barge, then float to the side, and unload to a conveyor taking the rock up the bank to trucks. I suspect they're doing that with those barges also, loading in one spot, then swapping to a empty while they float the full one over to shore to unload it.
I saw a tug boat in what I think was the upriver side so maybe they are using that to shove the rock barges around.
Birken, there are at least 2 tugs stuck on the upriver side. I don't know how or where they are gonna unload the barges.
Here is a good photo sequence http://www.sacbee.com/news/state/california/water-and-drought/article135860663.html
Here are some videos that just appeared of unloading barges, and also building "pads" which I think may just be stock piles.
Explanation and more pictures of work
I saw the evacuation etc on the news. They kept on about a thirty foot wall of water could come down the river. The spill way had broken up and the spill water was making its own way down. How would this translate in to a thirty foot wall of water if the main dam was was in no danger? Graham
They had shut off the damaged control spillway with the gates and let the lake level rise until it topped a concrete wall which is the emergency spillway built at a level lower than the actual dam top. It's to the left of the damaged spillway. This had never been used and to apparently everyone's horror the immediate effect of the water blasting over the top of the concrete structure was to begin eroding away the outboard toe of this emergency wall. The assumption was, probably correctly, that the continued flow of water would soon destabilize the whole concrete wall and when it failed the top twenty to thirty feet of the reservoir would be released. God only knows if the rest of that whole slope would have slowly been destroyed or been subject to a cascade failure creating maybe a 200 foot wall of water headed for Sacramento. The short period of time the water ran over the top of the emergency structure it wiped out the access road below it and the power lines connecting the power station with the grid I believe. The only choice left was to open the spillway gates wide and watch as the water carried most of the hillside down into the channel below but they avoided a much more catastrophic failure. Only just, and by luck and the grace of God moreso than any rational decision making.
I don't think there would have ever been a wall of water. The news loves to hype stuff up as you know. The Sheriff probably decided himself that the evacuation time window was closing if anything bad should happen and he wanted to have the people out of there before the water started to rise instead of after. More probably the emergency spillway would have started to eat away itself in one section and begun to lower slowly until it chewed down to bedrock but that 30' of water would have come out quite a bit faster than the 100,000 CFS they were releasing, but most importantly, uncontrollably and unstoppably until it chewed down to stable rock and would have slowly but unstoppably flooded miles downstream as well as released millions of yards of dirt into the waterways. My impression before all this started was that the emergency spillway would have been operating more or less within its intended design had this happened. When they used it the way they did, they were attempting to gain more control from it than it was designed to provide. Anyway, back to the rock pile they are working, in the above video it is now estimated 1,500,000 yards of material to move.
Channel taking shape. May be flowing tomorrow.
Very impressive operation, can't believe the material thats been moved in the last few days. Ed
Hopefully the weather will cooperate and they get the river channel open so they can start the hydro electric flow water going again . That would sure help releasing water . My understanding is the lake has three places to release water . Hydro - electric station The concrete channel that got wasted causing all the damage & erosion . Pretty big looking channel after looking at the videos posted by Birkin . Couple hundred foot wide & 25 foot deep ? The emergency spillway ? 1,700 foot wide concrete area where water can go over when everything else fails . Yet with the steep grade involved no concrete or erosion control for that situation ? Granted , I know it's California and the dam was built in the early 1960's and with drought conditions normally no one ever thought the emergency spillway would ever be used . They sure needed it on this storm system and were not able utilize it as such . When bucking mother nature trying to control water better have a good back up plan for worst case situation . Somebody crossed there fingers in the deal thinking it would never happen and it did .
There is a fourth place to release water. In the base of the dam there is a river release valve. Not very big, only a couple thousand CFS. As you might imagine 600 feet down it has some pretty good pressure. Therefore it pulls a lot of air along in a venturi effect when opened. Apparently they were testing opening it sometime before all this started and the operators were nearly sucked in by the vacuum and killed. So they have pretty much not considered that option any more.
It looks like a reincarnation of the Bloomfield hydraulic mining operations, https://en.wikipedia.org/wiki/North_Bloomfield_Mining_and_Gravel_Company
It's a bit of a worry when emergency spillways fail to perform as expected. The Wivenhoe dam here sits above the city of Brisbane with a population of over two million. Almost as soon as it was completed in the early eighties, engineers concluded that they may have underestimated the probable maximum flood inflows by as much as 200% In the last ten years, two emergency spillways with a system of fusible plugs have been installed to prevent the wall being overtopped in a 1 in 65000 yr. rainfall event. I wouldn't like to be in Bris. when those plugs let go. It's interesting to note, that with a catchment almost as large as Lake Oroville's, (at least according to Wikipedia), the gated service spillway on lake Wivenhoe has at least twice the capacity.
65,000 year event??? realy? I'm just a lay person, but I usually hear about hundred and thousand year floods, maybe a ten thousand year event. I can't imagine trying to design for a 65,000 year event. This main spillway failed for lack of maintenance (my opinion) in 50 years, compounded by the hydro generating station being offline (lack of maintenance. It seems ridiculous to plan for that long a timespan with the state of human affairs as they are. Edit: Maybe you meant 5,000 year rain event, that would make sense (if you're more optimistic than I am about the state of human affairs)
Nope, definitely 65000. Of course, there is a small chance that such an event could happen at any time.
I think I understood that the big scare was the dirt portion of the dam to the left of the concrete spill way as you look towards the lake being overtopped and washing out within minutes. That kind of event would likely have developed a wall of water running down the valley somewhat like the tsunami films in Japan. A similar event in Washington State was the eruption of Mt. St. Helens and the resulting flood and mud flows down the Touttle River drainage. It's nice to see a lot of big equipment working again even though caused from a disaster.
I don't think it was a Japan tsunami scenario. They were not going to lose the whole half mile of spillway at once. Rather if they lost any of it, they would start having an uncontrolled release that might get bigger until it got down several feet to several tens of feet. That lake is enormous, and it is a lot of water. They did not want to be dealing with that amount uncontrolled.
Numbers I just watched on Juan Browne 60,000 yd3/day moving 1,700,000 yd3 debris about 10% of that already moved Pretty good rate of progress I would say.
How many Artics you figure they got running there... 30+? They even dredged up a Koehring hoe yeah?
The gray cab and the cab being on the left side of the boom makes me think it's Hitachi. Did Koehring ever make a hoe with the cab on the left side?
I love videos like this showing some of the large scale engineering involved in building these projects.
No, you're right it's a Hitachi... I was just having flashbacks, LOL
I saw last night they had started the power plant again and were ramping it up but now it seems to be back at just one turbine running.... http://rdcfeeds.redding.com/lakelevels/oro.cfm Hopefully they get it up to full capacity soon. Found another video with some more cool building clips and stuff!!
Even with below freezing temps in the mountains, the inflow is more than double the max capacity of the powerhouse. The spillway is gonna have to be put back into use soonish to keep it under the 860' level they decided on. Apparently the plan is to release around 40,000 cfs to gvie the water enough velocity to clear the end of the spillway to keep the undermining to a minimum. Drone Video from over the weekend
Who are the Contractors performing this work?
I have no info on the work or contractor. I just know an enginerd out there that is keeping an ear to the ground.
Some of the hoes have these guys name on em' http://www.lundconst.com/
A member of another forum is one of the rock truck drivers, he said they moved 1100 loads yesterday on the side of the cut he was on( split into two sections to help with traffic), if the other side moved the same it would be around 60k yards in one 12 hour shift, they are running 24/7 so could be around 120k yards per day.
Syblon Reid is one of the big ones but I bet everybody has been invited to this party.
A member on Moparts is working there, last week he had worked 21 days straight, took 1 day off, then back at it. He's not said who he works for or what he's running. Ed
They were one of the ones mentioned in the news that fired some guys for posting spillway pics on the internet. I see the power house is going again with 2 turbines
Am i crazy or does that one 390 have a terex wheel loader bucket hooked on?
^^ Well.... it is the right color hard to say it has top reinforcing similar to a regular digging bucket... but you can see much wider gussets on the back also???
Whatever it is, that machine is right on it's limits, when he picks the bucket out of the water and when he goes to dump it, the machine lifts the rear track.
Yair . . . Buggered if I know, its' not my field at all but that flume, sluiceway, call it what you will is no where near as heavy built as I would have expected . . . like I mean to say the floor and walls maybe eighteen inches thick? What am I missing? I was involved in the dirt work on one large dam and watched them pour the spillway . . . many feet of solid concrete and steel and I believe even that one is having issues. Cheers.
I had the same thought Scrub, will be interesting to see what the rebuild will be!
Ditto that, Scrub. I know that we can't see the structure that has been washed away, but the remaining parts don't seem to have any deep attachment to the underlying bedrock. No keys or pilings seem visible under the spillway floor.
This model of efficiency is how they are unloading the barges. The cutting edges on the thumbs are a nice touch.
^^ Yeah, I saw one of the other videos when they first started that... it was painful to watch.
Meanwhile the guy with the green bucket on the main pile is picking up his back track with every fill and dump...this here is taking place in an out of the way spot. Either milking it because nobody's watching or they didn't put the sharpest hand on this particular machine. I have seen several videos of this operation over the last several days and they all look about like this.
It's an interesting repair, I would think they need to replace the upper section also. The water must have gotten started under the concrete to undermine it that way.
Yair . . . Can't quite get my head around what is going on here, what is the purpose of all the digging in the channel? I assumed this was the turbine outflow couldn't all that be flushed by increasing the flow? Cheers.
It was the rock that eroded when the spillway broke and they were forced to keep pouring water through the break. The power plant is at a very low level because it can also pump back uphill to the lake. So any raising of the pool and it does not work. 1.7 MM yd3 last I heard. Many of the boulders were nearly filling the bed of those rock trucks individually. https://en.wikipedia.org/wiki/File:Oroville_dam_infographic_feb_14.png
The chief/engineer discussing where they will get enough resources to rebuild the spillway this summer. He wasn't sure if there was enough in-state or the whole west coast. http://www.chicoer.com/general-news...wer-plant-increased-to-maximum-discharge-rate Something tells me this digging operation is only a drop in the bucket compared to what construction will be coming.
Yair . . . Gotcha Birken Vogt. Thanks for explanation. Cheers.
They were unable to use the power plant until they dug out the channel enough to lower the pool level at the outlet. They are also trying get all the loose rock out of the channel in the hope they can run the spillway without making the power plant inoperable again. DWR raised the max lake level another 5 feet. They hit the previous max sometime yesterday and i guess they didn't feel like turning on the spillway on yet.
A recent flyover.... Just a side note, it is amazing the amount of nonsense that various attention seeking internet people have taken footage from various sources, slightly modified it and claimed the dam was going to fall into the ocean and everybody north of San Diego would be drowned. And also that the Illuminati are quietly slipping out the hundreds of tons of gold each night that they are getting out of this rock pile.
All kinds of cool stuff going on in the video from Friday.
Rather awesome video! with that heavy downslope, it looks like they need some air injector slots to cause the turbulent flow to happen sooner! The dam is totally going to end up in the ocean, probably in less than a half million years too.
Been following this series. Least amount of hype I could find.
Fired for what? Are they trying to hide something? Or are they just being that funny about guys having their phones with them?
Company policy of not posting photos of the job site. I expect they always had this policy in place. You know how safety nazis and environment nazis and air pollution nazis and whoever's hands this might fall into might damage the company. I would enact the same policy. Too little to gain, too much to lose. And having dealt with the ignorant media, the less ammunition they have to hang you or your employer with, the better. The media was really out for blood a couple weeks back asking all sorts of accusatory and ignorant questions at the press conferences. They seem to have tamped that down pretty good. I am sure there are problems but the media has about a 0% chance of digging up real truth and delivering it to you so the less rocks you can give them to throw back at you, the better. Juan is a commercial airline pilot and also moonlights for a civil engineering firm here so he is of the analytical mind type to give facts and not spin. Also he is doing this on his own time. Lives just a mile or two from here and went to the local paper so he could get a press pass and went right in there with the Director and head engineer and helicopter pilots and everybody and asked intelligent questions. Most others you find on YouTube are just regurgitating video they ripped off from elsewhere and have little to no first hand knowledge and are just trying to get clicks. Some other locals are Pee Wee the Pinstriper and E 72 Knight though he tends a little toward the conspiracy side, at least he is in there generating his own video and story.
I too think it's company policy. They should have posted those anonymously. If they're trying to hide something, that's the only way people will know what's really going on with the spillway and the repairs.
Supposed to be a free country? Not only that but we the tax payers are footing the repair bill, we should have the right to know and see what's up!
It is free if you are there freely. If the boss is paying your wage you have to do what he says, quit if you don't like it. Which is effectively what these guys did.
It's a safety issue also, that jobsite is organized chaos, enough things to worry about let alone a bunch of distracted operators taking pictures and videos. I'm frequent GM plants for my job, on the factory floor there is no walking and using a phone allowed. Would guess someone walked into the aisle and got pasted by a forklift. Ed
My grandfather worked on that dam . 8 or so years ago I worked in that dam on the powerhouse . Wish I was still on with SRC cause I would be there right now . I had some really cool pics of it be built by grand daddy .
The company I worked for and most of our clients had a no photo without permission policy. I don't know how many times I have seen photos in the newspaper of some idiot hamming it up in a photo while committing a dozen OSHA violations. Fortunately, not on my jobs. Always fallout for the contractor. We let the media take photos and write stories but we always checked the stories to see if they got the facts straight and we checked the photos for safety violations. Its amazing how a reporter with no clue about the project can accidently twist up the facts and stir the pot. They usually are grateful for the time spent helping get the story factual.
It would be cool if you could post some of the build pictures.
So much for accurate climate predictions. California is at the forefront of 'global warming prevention' and the 'practice' of climate science, and yet they can't predict some winter rain! DWR nearly destroys a dam, because California knows so much about climate change...
Flyover of the whole situation. Good before and after of the rock pile. Looks like they are going to turn the spillway back on again soon so there will likely be a new rock pile only much smaller. With all the machines and systems in place I am sure they will make short work of it.
Somebody found asbestos in the rock. Bureaucracy kicking in attempting to do what it does best, move the whole operation into super low gear.... http://www.orovillemr.com/general-n...ound-in-spillway-rock-dust-controls-increased
From the "If it ain't broke don't maintain it" school of stupid: http://www.orovillemr.com/general-n...broke-show-something-wrong?source=most_viewed
If I could I would but after the divorce all pics are gone . I had thousands of pics from late 50s to current all gone . Grand daddy worked on I 5 , orroville , San louis , California aqueduct , I 80 , US 50 , Grand Coulee , Friant , Kern Friant canal , Cleared the dust bowl and the list goes on . I had pics of all of that . The two pics I miss the most was of him on an rd8 when he was young and the other was him on a d8L . He sat on and skinned all those cats . Long time in the seat pulling sticks !!!!!
Thats to bad. Lots of cool history gone. The old photos are so cool to look at. Recently after 20 years my X sent a single small set of slides that I had taken in the 70s. Looking at them against a lite I believe they are dirt photos of when the Big Stone City power plant was build in the early seventies. I need to get them to someone that can get them digitized,
Looks like they turned it back on...we'll see how it does this time.
Sounds like a full life of interesting and important jobs, bet he could tell some stories. Sorry about the pics, they could have just as easily been saved for you.
I just wonder who polluted all of that rock with asbestos; it's not like asbestos occurs naturally in the environment... (/sarc) Plenty of water for dust control... just wash all of that dust down river to San Francisco...
Here it is with the water coming back on, and some discussion of the upcoming activities.
Seems like with the time they had they could have thrown in some H pile, lots of I-beam and channel, zipped together a few dozen flatbed loads of sheet pile laid flat and built a flume off the end of the remaining spillway, but then I don't have all them letters after my name so what do I know?
I don't quite understand why nobody walked in the spillway during Aug '16 inspection, given that it's previously needed repairs '09 & '13, was built ~50 years ago and is possibly the most important feature of the dam. If it was my dam, I'd want to be walking on that shute after every significant use. No letters either tho, just a peasant engineer!
I read somewhere that due to the water level being above a certain point and safety policy they would not allow anyone in the chute due to possible failure of the spillway gates. Apparently the safety of the millions of citizens below the dam never entered the equation, it's all good right? Also obviously they never thought of using a drone or helicopter to inspect the spillway for faults. Pictures clearly show a small area that looks to be damaged or irregular at exactly the spot where the breach eventually occurred and another picture taken as water begins to flow shows significant turbulence at that spot. Ipso facto, what could have been prevented with a few hours repair work will now cost North of a Billion easily before they're done replacing the spillway and repairing all the damage to the slopes and channels. Complacency and Karma can be a bitch combination.
I thought the Army Corps of Engineers were in charge off all big dams, that must have changed as there is no mention of them that I've heard.
This is and always has been a State project. ACOE is for Federal dams such as Shasta, Folsom, etc. There is another huge dam near here called Bullards which is a local water agency. Most of the Fed dams were build in the 1940s or thereabouts. In the 1960s state and locals wanted a piece of the action so they built some of their own for their own purposes. Oroville is and was for Southern California and any other use is ancillary. Power generated here is consumed pumping the water there. Of course the Feds and ACOE have something to say about operation, etc. because they own the levees (usually) and just because they can I suppose.
All those excavators floating and parked when all they really need is Big Muskie and one guy
Indeed.... of course if it still existed in running condition it would take a year to mobe it in there and get it going.
Well that sounds like moving at California construction speed! Yeah it doens't move or drive too fast when it was around but boy, it'd dig! 20 million tons an hour might be a bit much for a couple haul trucks.
LOL, yeah, wouldn't need haul trucks, good man with the dragline bucket probably throw material a quarter mile!
Big Muskie did 8000 yds. an hour. At 3000 lbs per yard that's 12 million tons.
O-I-H, I know... It's like wondering who put the mercury in the ground at New Idria...
Dang, Scott, that's quite a picture to start the video. I wonder what the white patch-stuff is.
Concrete repair I'd guess. Possibly at the failure point for the spillway but not much is certain being that most of the spillway is missing. New developments. Sounds like they will have to open the spillway at least a couple more times depending on rainfall and snow melt. November really isn't that far away to the next rainy season. The clock is running mighty fast.
Just to keep the thread complete Also plausible theory about the I85 bridge/overpass collapse.
The CA Dept of Water Resources repair plan for the Oro Dam spillway shows the extensive use of roller compacted concrete. This is new to me; I only knew of rcc 'paving'. Evidently rcc is used to build dams! https://en.wikipedia.org/wiki/Roller-compacted_concrete
I knew of RCC as dam material long before I ever knew it was used for roads. Funny. I have never seen an RCC road, yet.
A vid showing the general process.
interesting report...
Link to the PDF report for those who don't want to give the LA Times clicks. https://assets.documentcloud.org/documents/3672058/Oroville-report.pdf
Do not care how they treat it or compact it it is the nature of concrete to shrink and swell with moisture and or temperature. It is going to crack, just how bad is up to the elements and the batch master.
In the most recent video Juan mentions something like 30' square slabs with sealed expansion joints. Not sure how they are going to do that but it sounds like the right idea. Remember in the pre-failure videos how much water was pouring out all the drains.
Brown water even, much more scary! But the volume of water was impressive. Maybe slabs with rebar pockets and pins and that nice goop they glue runways together with.
hvy 1ton, thanks for posting the link to the report. Looking at the report, it doesn't surprise me that the spillway was in a poor state of repair. California has been 'running on empty' for many years. The California DWR never had enough 'time or money' to maintain and fix the spillway, but they are 'heros' now, and they will replace or repair it in an 'amazingly short' amount of time. For an amazing amount of money.
It wasn't just poorly maintained, it wasn't designed or built all that well either. The fact that a lot of the floor was poured on weathered rock probably takes the cake. Runner up, they had water infiltration issues in the sub base before they finished pouring the spillway. Second runner up, the trees the inspectors asked them to remove i don't know how many times.
Now it starts...the never ending barrage of weenies who want to slow it down one way or another http://www.sacbee.com/news/state/california/water-and-drought/article154942329.html
Doesn't seem to be slowing much...
Progress.
Some video from the DWR.
I gotta say Juan Browne is one hell of a Journalist. Hope he gets to write off all of his flight time
I wondered how they got that rock so clean with just fire hoses, now I see, rubber squeegee (cut up old tire) on an excavator.
I was watching them wash and scrub and thinking, open the spillway a bit, it'll wash everything off in a hurry even with the gap in the upper spillway, maybe use some of that 18 inch heavy wall flexible plastic pipe, start a siphon and aim it with the excavator.
The crew next to the squeegee has a hydro blast unit. Not your average power washer.
Well true, looks like a high pressure fire hose arrangement, though the unrestricted flow of water carved out Croyle canyon in a hurry Thanks again!
All right time for some updates
Appears they are dealing with a great deal of 'Rotten' rock; Too soft for the necessary base but strong enough to be in the way. Also appears they are using a material we call 'Flowable Fill' and or 'shotcrete' here which in a proper form can be excavated yet retains the strength of concrete when solidified. Still looks to be a mess to recover.
I don't believe they are using flowable fill or any low strength product. My impressions are: first they are blasting everything down to bare solid rock. Then if necessary they consolidate cracks and such with "dental concrete" which they explain in the last video, it is high strength but flows in but only in small volumes. Then for the huge lifts of the eroded areas they are using roller compacted concrete which is very dry and has no rebar but is placed by dump trucks and dozers and rollers. In some places they use leveling concrete where they don't need such a lift I guess. Finally they place structural concrete with rebar and drains and walls and such for the final structure much of which will be done next year. But some is going down now. It has a special erosion resistant finish. They have made kind of a temporary chute with walls and such in some areas out of RCC but no rebar or drains or any features which will have to be demo'ed next spring for the proper placement but it is something to get by over this winter. The plan is if it has to be used this winter some of the work will be destroyed but most years it never gets used and I am sure they will take extra care this winter to avoid using it if at all humanly possible.
They used RCC on the replacement structure of the Taum Sauk reservoir, to replace the compacted rock fill they used decades ago with a concrete liner that had failed. http://www.concreteconstruction.net/products/taum-sauk-upper-reservoir_o
RCC going over 100 feet deep in a few weeks, that RCC must be some dandy stuff!! Birken, sounds like you live pretty close to Juan, maybe do a guest appearance!
Wunder what its like working on those dozers, rollers after they been pounding on concrete.. or do they ues a release agent on then?
Goes up in shallow lifts where each layer is compacted to the last, almost dry and compressible. Still generates heat needs some moisture to start the process, has plusses and minuses. Effective if done right worthless if done wrong.
Impressive progress. Ed
Problem is its still concrete and as hard as they try will still environmentally crack or shrink and pull at expansion seams. Best laid plans may sound good and cost a lot but longevity is the key, will it last?
It's probably not a bad thing that they don't have time in one season to finish the rcc with the structural concrete, that they get a chance to remove the top layer and have another go next year. 100ft of concrete placed continuously, I can't imagine the heat and expansion it will be going through, then cooling down later and contracting. Think the going back again approach is a blessing.
Update
In the video the narrator said they were applying RCC shotcreke on the wall. I wonder if he mis-spoke on that. We have shot shotcreke for years that had structural strength of up to 5,000 PSI concrete. What they were spraying in the video on post 134 looked like standard shotcrete and did not look like a water added product like RCC. I stand to be corrected.
Sounded like he said "here's the scaffolding on the the RCC walls, they're spraying shotcrete on wire mesh...." Etc etc A lot of good work going into a wall they may not use, and which is being pulled out to put drains in later; really impressive work especially with all the camera action watching every move.
Topped out the RCC.
Phase One complete.
Amazing, they seem to have got this done almost to the day they said they would. Cut out the red tape.
Work continues.
Kiewit being Kiewit, a remarkable company and remarkable people...
The hero is Peter Kiewit Sons Company and their people.
Hope this is further along and ready for water by now, with the storm rolling in off the coast may have to be used.
The lake is currently at 712', releases can't even start until ~830, and there has not been a drop of rain since May anyway, so the ground will probably soak it all up. They are not really "under the gun" until January normally, though they try to get work finished by November.
Thanks Birken
How was my price prediction on post #1?
Spot on, but does that include the landscaping charge...!?
Juan actually asked the question near the end of that video, about re-contouring the mountain side, and he seemed a little surprised when they said it was included, so I think that really is close to the final price tag. My feeling is that bulldozing the roads off and replanting the sticker bushes on the hillside is very small potatoes compared to what they did already, filling up a chasm with RCC and covering another mountain side with it. I think maybe next year it will be open to the public again, and I will go take a walk around myself. The scale of this thing is enormous, at one time it was the highest dam anywhere and it is not a thin concrete arch, it is an earth embankment. [man made mountain]
I don't know.... On jobs we do the 'finish work' always commands a pretty steep price!!! especially with all the 'green' stuff involved anymore, wouldn't be surprised to see a 10 percent/job for finishing.
Definitely the "glory" part of the job, the final clear up and beautifying. Would think / hope it's a satisfying end to a job well done.
I'll give you a dollar if you sneak over there with 5 gallons of green lawn dye and make a green spot.