Rains have returned (a little fire reprieve). Oroville Airport recorded 0.37 inches of heavy rain near the hours of midnight Oct 19 to 1 am Oct 20. Other areas in the hills had up to 1 inch of rainfall.
Posted on 02/12/2017 4:26:47 PM PST by janetjanet998
Edited on 02/12/2017 9:33:58 PM PST by Admin Moderator. [history]
The Oroville Dam is the highest in the nation.
I will also add that the contractor would virtually never be the one to announce that they had secured a number of large change orders which caused the budget to be overrun. They don’t set the budget — the Owner sets it based upon what is known before the project starts. The contractor has no idea of what overall budget is in most cases.
Strictly from the perspective of managing the Public Relations Side, DWR made a decision to announce this large overrun now when it can easily be demonstrated that DWR would have been aware of this months ago.
An astute press will pick up on this. This creates a potential for new questions from the press that could complicate DWR's PR management.
For example: Erin Mellon, DWR spokesperson, stated emphatically that the original spillway was built upon "extremely competent rock". She also stated that they were aware of the historical records regarding the sub-base geology. Now that Kiewit is on the record stating that these large cost overruns were from significant deeper excavation and much higher volumes of concrete, DWR's prior statements make them look highly incompetent (or foolish).
Given this known embarrassing conflict, is there a possibility that DWR chose to wait until the PR looked the best when the spillway is near "shiny new & almost done"? (for the 2017 phase).
Too many examples and incidents have happened that re-inforce a PR motivation to events - in spite of real hard questions of true Safety Engineering conditions (such as headworks cracking, anchor tendons, and the "PR" version of "rainfall" dam report).
Until DWR establishes a record that gets away from this shade of PR motivation, there always is a lingering suspicion to events and actions.
It doesn't take much to figure out that the media does not have a full trust in DWR. Perhaps new news articles may be forthcoming that touch on this situation (overruns & timing).
Oroville Dam: Cost to repair spillways nearly doubles in price to $500 million
By Paul Rogers | progers@bayareanewsgroup.com | Bay Area News Group
PUBLISHED: October 19, 2017 at 3:26 pm | UPDATED: October 19, 2017 at 7:39 pm
OROVILLE — The cost of repairing the crippling damage to Oroville Dam’s spillways caused by last winter’s fierce storms has almost doubled, state water officials said Thursday.
Kiewit, the Nebraska-based construction firm that has the main contract to rebuild the main spillway and emergency spillway at Oroville, the nation’s tallest dam, estimated in its winning bid in April that the work would cost at least $275 million. But the price tag has now grown to at least $500 million, said Erin Mellon, a spokeswoman for the Department of Water Resources.
“When Kiewit put in the bid, only 30 percent of the project had been designed,” she said. “When you get on the construction site, there’s a lot more information that you glean.”
Jeff Petersen, project manager for Kiewit, said that once construction workers got on the site they discovered they had to dig much deeper to get down to bedrock than they had expected. That meant they are having to pour almost twice as much concrete this year — 870,000 cubic yards — as the company and the Department of Water Resources had planned.
Petersen said such discoveries are not uncommon on major dam projects.
“It’s like when you work on an old house or an old car,” he said.
Petersen said the project remains on schedule to hit a Nov. 1 deadline for repairs that will allow the main spillway to carry up to 100,000 cubic feet per second this winter. Seven hundred workers are rushing around the clock.
“I don’t want to jinx it,” he told reporters on a tour of the construction site, “but we’re five days ahead of schedule.”
On Thursday, the scene inside the main spillway — which is 3,000 feet long and 180 feet wide, twice the width of the Golden Gate Bridge — was abuzz.
Huge cranes swung steel beams and other materials overhead as fleets of giant dump trucks poured layer after layer of concrete, and bulldozers and mechanical rollers compacted it. Diesel engines roared from all directions, and the constant beeping of heavy equipment filled the air.
Additional work to finish the emergency spillway and cover the entire main spillway with reinforced concrete is scheduled to be completed by the end of 2018. About 41 percent of the main spillway will have concrete with modern rebar by Nov. 1.
Mellon said the state has asked the Federal Emergency Management Agency to pay 75 percent of the cost. The rest will come from contractors of the State Water Project, including the Santa Clara Valley Water District, the Alameda County Water District and the Metropolitan Water District of Southern California.
One other large expense of the February disaster is coming in lower than expected.
The original cost estimate for the emergency response — which included using fleets of helicopters to drop boulders, emergency concrete pouring and moving huge high-voltage power lines — was $274 million. In the end, however, it looks as if the actual cost will be between $140 million and $160 million, Mellon said.
Mellon said state officials are computing numbers now and more precise estimates will be ready by Nov. 1. “It’s an evolving project,” she said. “Most are.”
In early February, relentless winter storms dumped nearly 13 inches of rain in four days on the Sierra foothills. Waters raging over the dam tore an enormous hole in the spillway, leading to an unprecedented emergency that prompted the evacuation of 188,000 people from nearby towns.
After the hole developed, the Oroville spillway became an international story. State officials closed the gates on the main spillway, and the lake level rose to the top. Five days later, water poured over the emergency spillway, eroding it so badly it looked as if it would collapse.
Butte County Sheriff Kory Honea issued an emergency evacuation order with phrases like “This is NOT a drill” spread across social media, radio and TV. Chaos ensued.
Stores closed. Gas stations were overwhelmed. Panicked motorists drove on the shoulders of Highways 70 and 99.
The fear was that if the emergency spillway continued to erode, the top of the lake’s rim could give way, sending a wall of water from the 10-mile-long lake — California’s second largest reservoir — to the communities below.
State water officials made a gambit. They reopened the badly damaged main spillway to lower the lake. They knew the water — flowing at 750,000 gallons per second — would rip it apart, but they hoped the violently out-of-control flows would not start eroding away the face of the dam itself.
The plan worked. The lake level dropped. Water stopped flowing over the emergency spillway. The dam held. And two days later the evacuation order was lifted.
After the state put the repair job out to bid, Kiewit came in with the lowest price. The company, which also built Los Vaqueros Dam in Contra Costa County in the 1990s, went to work on two primary jobs: shoring up Oroville’s main spillway by filling in the chasms that had eroded and pouring new concrete — and building a new underground retaining wall at the hillside that functions as the dam’s emergency spillway, with layers of new concrete to reinforce its top.
An independent “forensics team” ordered by federal regulators to find out what went wrong at Oroville issued its preliminary findings in May, citing defects ranging from the dam’s construction in the 1960s to problems linked to poor maintenance and oversight by state and federal officials. Its final report is due this fall.
The new main spillway will be much stronger, Petersen said. Its concrete is between five and 13 feet thick in most places, with 612 concrete slabs each connected to 14 steel plates holding anchors drilled 20 feet or more into the bedrock.
After work began May 20, crews were in a race to stabilize the main spillway in five months.
“It’s not the biggest job we’ve ever worked on, but we usually have more time, compared to other jobs,” Petersen said. “We mobilized 500 pieces of equipment in 30 days.”
Construction workers have come from as far away as Alaska, Texas and Colorado, although 90 percent are Californians. In the summer, they worked in temperatures that exceeded 110 degrees inside the massive main spillway.
Several months ago, state officials decided to move the location of a huge underground concrete wall designed to prevent erosion on the main spillway from 350 feet away from the reservoir’s edge to 732 feet away. They had to do that to find solid bedrock. That decision doubled the amount of concrete armoring on the hillside, increasing costs.
Another driver of the higher-than-expected costs was the fact that crews filling two giant chasms in the spillway up to 80 feet deep had to excavate up to 20 feet deeper in some places than they had anticipated to find bedrock. That meant more concrete was needed to fill the holes.
“It’s like when you go to the dentist with a cavity and he says, ‘This has to come out too,’” Petersen said.
Survey shows locals aren’t confident as DWR deadline nears
Taylor Torregano
Posted: Oct 18, 2017 06:00 PM PDT
OROVILLE, Calif. - As the deadline approaches to have the Oroville Dam spillway fully functional for this year’s rainy season, Assemblymember James Gallagher revealed results of a survey he sent to nearby residents.
The survey put into numbers the strong distrust Oroville locals feel towards the Department of Water Resources (DWR). Assemblymember Gallagher sent the survey to people living in the evacuated areas from February’s near catastrophe. Of the 3,322 people who responded, 84 percent said they are more concerned with the operations and maintenance preformed by DWR than they are of terrorists.
Still, staff with the DWR only continued to reiterate that public safety is their first concern. “It makes sense that the community would be more concerned with operations of their lake because groups like Homeland Security are the ones who are worried about terrorists,” responded Erin Mellon, assistant director for the Department of Water Resources, Public Affairs.
That is why the DWR said some of the records it has posted to its website have been redacted, calling it an order from Homeland Security.
In the survey, 78 percent of respondents thought the spillway crisis was manmade and preventable. In response, Erin Mellon said, “That’s exactly what the independent forensics team is looking at and we will wait and see their final report as to what caused the erosion in February.”
Despite only 12.6 percent of locals who believe this erosion will be fixed by the November 1 deadline in two weeks, DWR said it can assure everyone they will reach this milestone on time, but also reminded Oroville that this is just Phase One.
“Given the time constraints and the sheer size of this project it will take two construction seasons to completely reconstruct the main spillway,” said Jeanne Kuttel, chief of engineering at the Department of Water Resources.
The DWR has posted all documents, videos and pictures that are open to the public on it’s website, accessed by clicking here.
For a full look at the survey conducted by Assemblyman James Gallagher, click here.
I wish reporters would learn a little bit of engineering.... Ugh.
He seems to have been "spoon fed" a narrative from DWR (i.e. unprecedented storms)** & he managed to twist this up too.
There was no "water raging" over the dam. The water was flowing in the main concrete spillway, not running over the dam.
The flow rate was simply at 18% of the design rated capacity* when the spillway had its "blowout".
*Max design spec was 296,000 cfs. Blowout occurred at 54,500 cfs.
**Oroville was designed for a "Probable Maximum Flood" (PMF) that has much higher volume per time than what was experienced this last winter. So the narrative of unprecedented storms means that they are exaggerating as if the PMF cannot handle such flows. This is false, it's misleading, and is a "ploy" to seek FEMA funding as if their PMF is a natural disaster (logical conflict).
"DWR said some of the records it has posted to its website have been redacted, calling it an order from Homeland Security.."
Doing "weighted" Boolean reduction logic, this "flips" the Homeland Security focus.
I see your point a little better now. The main placements should be done in two weeks and Kiewit has kept ahead of the game pricing impact and burden of the extra work as they have gone along, so the DWR had a good view of the total financial revisions now, where a month ago they were still being encountered and the tab kept risings.
I think that they know the press will make some hay over the costs but it is not like how the press would treat a Republican administration. In California, there is little consequence for incompetence — its a given going in.
Rains have returned (a little fire reprieve). Oroville Airport recorded 0.37 inches of heavy rain near the hours of midnight Oct 19 to 1 am Oct 20. Other areas in the hills had up to 1 inch of rainfall.
Why did they build the new upper spillway sidewalls at different heights?
Also, I notice there are two “pie shaped” sections of finished slab
on both sides down at the lower end of the sidewalls.
As the water in the spillway gains velocity from its downslope flow, the height of the water lowers. (height = cubic feet per second [velocity] within cubic foot cross section of spillway and spillway sidewall.)
The original spillway had this height tapering on the steeper slopes of the spillway but they did not have sharp steps as Kiewit has built the new panels. The original spillway smoothly curved in this height change.
"Also, I notice there are two “pie shaped” sections of finished slab on both sides down at the lower end of the sidewalls."
Not sure what you are describing here. There is a safety fence with that angles like a "pie shape" on the ends of the fencing. This area is where they recently poured the massive "transition slab". The end of this slab should have a height differential and/or including a shape bevel to facilitate an "aerator" feature. An aerator is intended to induce a froth of air bubbles into the water flow from a pressure differential.
Shouldn't have long to wait to see this feature when the RCC to Upper Spillway junction is completed.
‘...Not sure what you are describing here...”
-
On the image you posted of the upper spillway
Look at the finished slab
adjacent to the lowest sidewalls on both sides
See those wedge-shaped sections?
Probably had to do that for the transition...
Also of interest, there is an image here:
https://pixel-ca-dwr.photoshelter.com/galleries/C0000OxvlgXg3yfg/G00003YCcmDTx48Y/Oroville-Spillway-Incident-Recovery
showing the installation of a drain pipe.
KJ_oroville_1666_10_19_17.jpg
currently image # 6 of 1649
Kiewit will need to construct "transition sidewall" slabs in this section to meet up with the RCC. It will be interesting to see how they perform this "meet up" in the sidewalls.
The other picture below is of the sidewall drain pipe they are preparing in the sidewall rebar. Clearly the original upper spillway will have seepage that requires drainage, besides the existing longitudinal drains for this section. Whether Kiewit connects other newer slab drains to sidewall drain pipe(s) in the upcoming construction should be revealed (perhaps in later seasonal work).
Drone footage has shown that the lower concrete section of the spillway has "open" drain pipe on the outside of the base of the sidewall slabs. It is not clear what the final drain design approach will be for this section. I've been waiting to see more clues.
"wedges" at the sides of the transition slab inferred to be construction "fill concrete".
Sidewall drain pipe being placed in rebar matrix before pour (upper main spillway).
Thanks!
A closer view of the construction fill concrete in the area of the "wedge" shape discussion. Another feature that is revealed is the flexible strip "waterstops" in the seams of the sidewall sections (white strip). These "waterstops" provide a seal barrier to water flowing into and through the expansion joint seams of the sections of the sidewall slabs.
The drains are "open drain" so far in this image (one is seeping water - likely from construction work). The outlets to each drain are not connected to a longitudinal drain as observed further up in the upper main spillway construction. In time, construction will likely reveal the final design.
Close Up View of Construction "fill concrete" - Sidewall "waterstop" strip
A glimpse of the last piece of exposed bedrock as the RCC has officially "met up" with the Upper Main Spillway. The large concrete block in the foreground is one of two placed deep below where the transition slab will have a "transition sidewall" linking the RCC sidewalls with the new Upper Spillway sidewalls. It's possible these blocks will serve as an anchor re-inforcement of these transition sidewalls. We'll see if these are for deeper concrete sidewall forms or for use as deep anchor bolt securement. It seems the latter as the RCC timetable won't allow much to be done with deeper form work.
RCC meets up with Upper Spillway - Oct 23, 2017
Construction Concrete forms in place for the lower height RCC transition sidewall (far side). Look close as the brightness of the image is not easy to see & with the sidewalls coated in white.
These deeper wall/panels likely will get their lateral structural integrity from being surrounded by RCC. Two posts up show a worker drilling into the transition slab for possible rebar anchors for these smaller sidewall slab pours.
Looks like the work will be finishing up since the rainy season in Northern California may start in November. Is the work on schedule? Can they continue even during intermittent rain?
So far there hasn't been any notification that they are behind their target schedule. Of course, the definition of being "on schedule" has flexibility on less critical functions. The most important keys to keep on schedule is what affects the functional operation of the new reconstructed main spillway.
The key piece now is the finishing up of the RCC section joining the Upper and Lower Construction concrete sections. I believe that they will finish these "joining" points in a few days.
The last big step is the finishing of the RCC sidewall junction at the Upper Main spillway "meet point" and then the application of a 1 ft thick layer of higher strength RCC (chemically enhanced) over the entire sloped RCC section.
Kiewit must have some automated RCC placement equipment to be able to do this 1 ft layer quickly. It will be interesting to see what they have to do this (remember the slope grade of the spillway is a challenge on top of the additional challenge of a "compaction" required on this slope grade).
"Can they continue even during intermittent rain?"
Generally, rainfall during RCC placement causes issues: Rollability, physical, and mechanical properties manifesting in water content, vibrating compaction value, density, and bonding strength to the sub-layer lift.
One method of dealing with a given rainfall is to compensate in the initial water content (reducing it). However, given the critical nature of this "hardened" or stronger surface layer I suspect that Kiewit would not risk having to deal with a fluctuating rainfall condition during the placement. They would wait for the appropriate weather.
Rainfall can vary from the intensity in the Oroville area just from its geography (Dam at base of elevation range/hills). On top of this, you have the variability in the rain precipitation concentrations just from cloud formations.
Kiewit has been very creative in their equipment and construction approach. I believe they have some automation waiting to be revealed for a quick application of this layer.
DWR is holding a Workshop to discuss in secrecy the 50 year old "end of life" Radial Gate anchor tendon "test data" on Oct 24, 25, 26 in Sacramento this week. Selected experts in the field of metallurgical studies, simulations, lab test comparison, will gather in this Secret "Workshop" to likely "vote" on a thumbs up or thumbs down (i.e. Safe with margin, or Unsafe with Unknowns).
Since DWR does not want any terrorists involved in this technical discussion, the meeting is being classified by DWR under Homeland Security's rule "Critical Energy Infrastructure Information" or CEII (sarcasm not intended).
Failure Danger in a "Secret Workshop" Process
Oroville's two disasters in the Main Spillway and Emergency Spillway was spookily identified in a prior FERC Part 12D analysis a few years ago. Yet the "vote" of thumbs up to thumbs down went against any who felt this scenario was real.
February 2017 proved the failure analysis of BOTH events and the failure sequence was accurate. So why were any dissenting views ignored? Shouldn't there be a unanimous decision, with supporting "proof" data, on such Safety Critical Infrastructure Dams? How did it get to a "vote" status?
The American Society of Civil Engineers have a code where Professional Engineers are required with an "Obligation to Safeguard the Safety, Health, and Welfare of the Public" in a responsibility to report wrongdoing (see below).
Why is this an issue with Oroville Gates & Anchor Tendons?
Because the full Headworks Must be analyzed as a "System". Any "condition" or "combination of conditions" that results in an "Unsafe with Unknowns" is unacceptable in a High Risk Dam Structure such as Oroville. This means that in a full "System", the flexure of the 16+ foot crack in Pier 10 (Gate 8) must be included in the impact of Gate 8 AND Gate 7 as they share any torsional anomalies. This means that in a full "System" any new "unknowns" in the metallurgical community MUST be resolved into "Knowns" plus margin. The Army Corps of Engineers could not explain 2014 results that showed a 70% variance of Anchor Rods (tendons) in a dam that had 39 year old anchor rods. Oroville's are 50 years old and have known "cracks" dating back to 1999-2000.
This means that in a full "System" the loss of steel re-inforcement corrosion of water penetration in the 5 foot thick Pier 10 MUST be resolved into "Knowns" plus margin. This means that in a full "System" a full analysis of the new failure mode of Tainter Gate Oscillation Failure MUST be resolved into "Knowns" plus margin (see Article clips below & link to article).
This means that in a full "System" the "Settlement" evidence of the diagonal cracks at the end Piers 1 and 10 MUST be resolved into "Knowns" plus margin. These diagonal cracks originate in a KNOWN design fault of separate support structures of the bridge columns verses the separate Headworks sections.
Prior evidential photographs in prior posts reveal that there are issues with Gates 7 and 8 in how DWR is operating them. The evidence points to either a torsional jamming effect or a chronic gate seal mis-alignment problem. Could these be related to a distribution of anchorage rod tensile stresses? DWR is keeping information bottled up in CEII status so no independent analysis may be performed.
A $500 million dollar new set of Spillways - with High Risk Gates?
Until DWR allows a transparent analysis of information on the full "System" will these answers become discernible to the degree of Risk imposed on the tens of thousands of residents below the Dam. In the interim, the code of ASCE is the only thread of application of "speaking out" like what should have been done in the years prior FERC Part 12D analysis that predicted the exact failure script Oroville experienced in 2017.
----------- ASCE (American Society of Civil Engineers): RESPONSIBILITY TO REPORT WRONGDOING (Obligation to safeguard the Safety, Health, & Welfare of the Public)
In matters of professional conduct, it is generally understood by engineers that they have an obligation to report illegal or unethical acts to the proper authorities. Canon 1 of ASCE's Code of Ethics underlines the engineer's paramount obligation to safeguard the health, safety, and welfare of the public, and category (d) in the guidelines to practice for this canon requires engineers with "knowledge or reason to believe that another person or firm may be in violation of any of the provisions of Canon 1...[to] present such information to the proper authority in writing and ...cooperate with the proper authority in furnishing such further information or assistance as may be required."
-----
Reference: http://www.asce.org/question-of-ethics-articles/apr-2011/
Will Oroville Spillway Gates Fail in Heavy Flows? Design Flaws & Fixes Risk Gate Binding?
Will Oroville Spillway Gates Fail in Heavy Flows? Design Flaws & Fixes Risk Gate Binding?
--- Article clips:
This event uncovered an astonishing amount of damage, broken parts, and design issues so serious that it led to the complete refurbishment to all eight of the Spillway Radial Gates. These issues are considered FERC Category 1 Failure modes that are of the highest rated level. Failures of Radial Gates have been known to lead to potential catastrophic outcomes including dam failures [10][11]. DWR's own report to FERC noted that a major cause was from "Lack of maintenance" - which caused the system to degrade and become clogged with mud and debris. How could a High-Reliability System be neglected to the degree to where the accumulation of mud and debris became a contributing failure mode? How many years of this type of maintenance neglect of this mud and debris have been going on? Forty years?
…
Today's modern Radial Gate designs have revealed a new and powerful force dynamic that was not well known years ago. Up to 60 ton Radial Gates have experienced a powerful "vibration" oscillation condition from critical flow levels in the gate openings. A standing wave of high and low pressure oscillation develops on the lower skin plates of the radial gate that transfers a complex set of distortions and movements to the massive steel gate structure. Indeed, experts are now attributing this powerful resonant oscillation vibration condition as a key component to the catastrophic failure of the Folsom Radial Tainter Gate in 1995 [11]. The power of this multi-mode form of oscillation in the massive trunnion gate structure would be dominant in forces applied to the Oroville Spillway Radial Gate design to these weakly coupled side seal assemblies. The wave action of the resonance would easily focus high forces on the side seal assembly individual aligning J-Bolts (now upgraded to eyebolts). This could cause either a shift in the alignment from "slip" or from "rotation" in the bolt compression area of the eyebolts. The result could be a swift and dangerous form of a strong binding condition to the gate in a virtual "freeze" state.
The Oroville spillway Radial Gates Side seal assemblies & mounting bolt architecture were not designed for these powerful "dynamic" forces from a 20-30 ton structure**. The side seal assemblies could be distorted and thus become overly pressurized in locations that could lead to an excessive frictional coefficient (i.e Binding failure). Other seal areas could excessively gap such that debris could flow into and lodge causing another degree of an increase in friction coefficient [13]. The modern upgrade solution to this failure risk is a ruggedized & adjustable mating assembly that could endure the higher dynamic forces over and above the vulnerable existing "slip", "rotate" and bend design.
A new design flaw has been discovered in a DSOD 2015 Inspection photograph. At least one of the radial gates reveals mis-alignment offsets of the welded flanges that are so large that the DWR to FERC identified solution of an eyebolt will not align. Thus, the photograph reveals that sections of metal, either a bar or formed metal, had to be bent upwards many inches to connect between the flange and the side seal assembly (see Fig 2, 3). This greatly weakens the alignment holding strength while adding a new failure shift mode (alignment rotation bending moment). Searching FERC/DWR communications & documents, there were no discussions where DWR notified FERC of this design modification. As far as FERC has been informed, the 2008 report (see Fig 4, Fig 3) has only the "straight" eyebolt design. This infers that FERC has not had the ability to provide feedback on the integrity of this new imposed design fix by DWR. DSOD Inspectors have commented on the flange to side seal assembly misalignment issue with the gates [2]. It is unknown as to how many of these significantly misaligned connections are in all or some of the eight Radial Gates. Mechanical deviations of this magnitude are significant regarding proper analysis in High-Reliability Systems.
--- end clips full article, images, and numerous technical references at link
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