Guest Post by James L. Gordon, P. Eng. (Ret’d)
I have mentioned several times that a review board is
essential for the North Spur.
essential for the North Spur.
Perhaps I should summarise the reasons
particularly since the Owner’s engineering consultancy – Hatch – has made the same
recommendation.
particularly since the Owner’s engineering consultancy – Hatch – has made the same
recommendation.
It is acknowledged that the North Spur natural dam is the
first time a dam containing marine clay and founded on a deep deposit of marine
clay has been used in a hydro dam. All major “firsts” always have a review
board to add assurance to the design. I have worked on three dam “firsts” and
all had review boards, and all benefited from their advice.
first time a dam containing marine clay and founded on a deep deposit of marine
clay has been used in a hydro dam. All major “firsts” always have a review
board to add assurance to the design. I have worked on three dam “firsts” and
all had review boards, and all benefited from their advice.
The first was at Duncan in BC, which is founded on a deep
deposit of unconsolidated liquefiable silt. It holds the world record for
settlement as predicted, at now over 6m. We had a 4-man review board which made
significant changes to the project layout, adding to security.
deposit of unconsolidated liquefiable silt. It holds the world record for
settlement as predicted, at now over 6m. We had a 4-man review board which made
significant changes to the project layout, adding to security.
The second was at Bighorn in Alberta, where the deepest (to
date) cut-off through gravel and boulders was part of the dam. There we had a
2-man review board, including Dr. A. Casagrande from Harvard. He made a major
change in the dam design which, on hindsight, avoided a possible dam failure.
date) cut-off through gravel and boulders was part of the dam. There we had a
2-man review board, including Dr. A. Casagrande from Harvard. He made a major
change in the dam design which, on hindsight, avoided a possible dam failure.
The third was at Jebba in Nigeria, where the dam is founded
on Aeolian unconsolidated sand blown in from the Sahara Desert. Again we had a
2-man review board including Dr. R. B. Peck, Professor of Geotechnical
Engineering from the University of Illinois, who suggested a consolidation
method which added significantly to the dam safety.
on Aeolian unconsolidated sand blown in from the Sahara Desert. Again we had a
2-man review board including Dr. R. B. Peck, Professor of Geotechnical
Engineering from the University of Illinois, who suggested a consolidation
method which added significantly to the dam safety.
 |
| James L. Gordon, P. Eng. (Ret’d) |
Every utility I have worked with has welcomed a review board,
with the exception of NALCOR, who adamantly assert that such a board is not
necessary, since the design has been thoroughly reviewed by professors and
other geotechnical engineers. Such is not the case, since any thorough review
would have discovered the glaring inconsistency in the liquidity-strength
relationship, as uncovered by Mr. Maurice Adams, in the test data for the North
Spur soils.
with the exception of NALCOR, who adamantly assert that such a board is not
necessary, since the design has been thoroughly reviewed by professors and
other geotechnical engineers. Such is not the case, since any thorough review
would have discovered the glaring inconsistency in the liquidity-strength
relationship, as uncovered by Mr. Maurice Adams, in the test data for the North
Spur soils.
So who has undertaken reviews of the North Spur?
NALCOR has affirmed that two renowned professors have
reviewed the design.
reviewed the design.
The first was Dr. Serge Leroueil from Laval University who stated at the start of his just over one-page review dated
24 August 2014, that “my knowledge on the
dynamic behaviour of soils and its analysis is rather limited. Moreover, I
received the main report but not the appendices”. His conclusions – “the stabilization works increase the factor
of safety from about 1.0 to about 1.6 which is very significant …….in the
section on Limitations and sensitivity, I have been surprised to read that the
granular material can be very sensitive to their saturation. This is true but I
am not sure that this aspect has been considered in the analysis” Certainly
not an endorsement of the design.
24 August 2014, that “my knowledge on the
dynamic behaviour of soils and its analysis is rather limited. Moreover, I
received the main report but not the appendices”. His conclusions – “the stabilization works increase the factor
of safety from about 1.0 to about 1.6 which is very significant …….in the
section on Limitations and sensitivity, I have been surprised to read that the
granular material can be very sensitive to their saturation. This is true but I
am not sure that this aspect has been considered in the analysis” Certainly
not an endorsement of the design.
The
other was Dr. I. M. Idriss, Professor Emeritus of Geotechnical Engineering from the University of California, Davis
Campus. He made some comments on the earthquake magnitude, but never issued a
report.
other was Dr. I. M. Idriss, Professor Emeritus of Geotechnical Engineering from the University of California, Davis
Campus. He made some comments on the earthquake magnitude, but never issued a
report.
Other companies which may have undertaken a review are –
The Independent Engineer, MWH. However, their mandate only
includes reporting on the construction progress for the Federal Government as
part of their loan guarantee.
includes reporting on the construction progress for the Federal Government as
part of their loan guarantee.
The Owner’s Engineer, Hatch has reviewed the design. I was
under the impression over a year ago, that they had undertaken a detailed
review, and one of their senior geotechnical engineers assured me that I should
have no worries about the dam safety. I was relieved, since he mentioned the
three geotechnical engineers who had looked at the design, and I had previously
worked with all three.
under the impression over a year ago, that they had undertaken a detailed
review, and one of their senior geotechnical engineers assured me that I should
have no worries about the dam safety. I was relieved, since he mentioned the
three geotechnical engineers who had looked at the design, and I had previously
worked with all three.
This resulted in my flip to pronouncing the North Spur
dam as being safe. However, on further investigation, I found that their review
was superficial, and I flopped over to again advising that the dam needed a
thorough review by a board of geotechnical engineers with experience in soft
sensitive clays. Now, Hatch do not claim to have undertaken part in the design
and only provided a computer program to model the seepage and effect on the
internal piezo-metric pressures when the reservoir is filled.
dam as being safe. However, on further investigation, I found that their review
was superficial, and I flopped over to again advising that the dam needed a
thorough review by a board of geotechnical engineers with experience in soft
sensitive clays. Now, Hatch do not claim to have undertaken part in the design
and only provided a computer program to model the seepage and effect on the
internal piezo-metric pressures when the reservoir is filled.
There have been several reports produced by Hatch. Most are
on the effect of ice, the dam safety monitoring and the pump-well system. But
there is a report on the design titled “Cold eye review of the design and
technical specifications for the North Spur. Jan. 2014.” which is worth a more
detailed comment.
on the effect of ice, the dam safety monitoring and the pump-well system. But
there is a report on the design titled “Cold eye review of the design and
technical specifications for the North Spur. Jan. 2014.” which is worth a more
detailed comment.
The review is based on incomplete data – “The review of the North Spur design relied
on the Engineering Report – SLI document No. 505573-XXXX – XXER- rev # which is
dated November 2012 (Ref 1). It is understood that this report is in a
preliminary form and does not contain much of the analysis and design that has
been undertaken more recently”.
on the Engineering Report – SLI document No. 505573-XXXX – XXER- rev # which is
dated November 2012 (Ref 1). It is understood that this report is in a
preliminary form and does not contain much of the analysis and design that has
been undertaken more recently”.
The liquidity-strength anomaly was not mentioned, but there
is a pertinent comment on the liquidity –“The
Liquidity Index (of the upper clay strata) averages 1.5 with a range of 0.7 to 3. Values in excess of 1 are an
indication of the potential for both liquefaction and flow type failures”. And
“The Lower Clay sits above the Lower
Aquifer generally between El. 10 to -50 m. This layer consists of clay of low
to medium plasticity with a liquidity index that would classify the clay as
slightly sensitive”. Sensitive clays are prone to liquefaction, but there
is no further comment on the dangers posed by the clay sensitivity.
is a pertinent comment on the liquidity –“The
Liquidity Index (of the upper clay strata) averages 1.5 with a range of 0.7 to 3. Values in excess of 1 are an
indication of the potential for both liquefaction and flow type failures”. And
“The Lower Clay sits above the Lower
Aquifer generally between El. 10 to -50 m. This layer consists of clay of low
to medium plasticity with a liquidity index that would classify the clay as
slightly sensitive”. Sensitive clays are prone to liquefaction, but there
is no further comment on the dangers posed by the clay sensitivity.
However, there is a comment that – “The sensitivity of the upper marine clay has been reported to be in the
range of 2 to 28 with an average of 11 as obtained from cone tests carried out
in 1979. This does not agree with the results from the 1978 Acres report which
indicate sensitivities one magnitude higher”. This discrepancy was not
pursued further.
range of 2 to 28 with an average of 11 as obtained from cone tests carried out
in 1979. This does not agree with the results from the 1978 Acres report which
indicate sensitivities one magnitude higher”. This discrepancy was not
pursued further.
Even Hatch recommends a review board with their comment in
the conclusions – “Further analysis on
the sensitive marine clays with regards to potential loss in strength when
subjected to seismic loading is required. This should be coupled with engaging
two eminent consultants with specific expertise on sensitive marine clays”.
the conclusions – “Further analysis on
the sensitive marine clays with regards to potential loss in strength when
subjected to seismic loading is required. This should be coupled with engaging
two eminent consultants with specific expertise on sensitive marine clays”.
Another concern is the steepness of the North Spur dam slopes
when compared with other dams founded on sensitive non-marine clay with similar
strength characteristics. The main example is the Gardiner Dam in Saskatchewan,
which has a height equal to the height of the North Spur dam, and is founded on
similar sensitive clay. The slopes at Gardiner are far flatter, and for the
North Spur dam to have comparable slopes, the base width would need to be more
than doubled.
when compared with other dams founded on sensitive non-marine clay with similar
strength characteristics. The main example is the Gardiner Dam in Saskatchewan,
which has a height equal to the height of the North Spur dam, and is founded on
similar sensitive clay. The slopes at Gardiner are far flatter, and for the
North Spur dam to have comparable slopes, the base width would need to be more
than doubled.
The bottom line – North Spur design reviews to date have been
superficial, and even the only worthwhile review by Hatch, based on incomplete
data, recommends a review board.
superficial, and even the only worthwhile review by Hatch, based on incomplete
data, recommends a review board.
Jim Gordon. P. Eng. (Retired).
Time for PEGNL to crawl from underneath their cloak of indifference to actually take a public position on this.
May be a regime change would alter the "Professional Reliance" model permitted by Provincial regulations. I support Jim Gordon's call for better review and scrutiny of earth dams. Related material from BC
https://thetyee.ca/News/2017/04/12/Mount-Polley-Disaster-Changes/
Any hope that the recent appointments to the oversight committee will bring us closer?
And yet we continue to spend hundreds of millions trying to put Muskrat back ON TRACK. The new review board is part of the HOPE of putting Muskrat on track.
On track is NOT possible…….especially with such incompetence continuing. And our local engineering association is silent…..not their mandate would be their likely response. Let the Telegram and CBC or even Pat Daley contact them for opinion on this. Otherwise the media is party to this boondoogle……..which has long been the situation………but imagine spending 12 billion and then losing the North Spur!
Uncle Gnarley`s and Dave Vardy`s opinion still seems valid…..put the project ON ICE pending a proper review for the wisdom of continuing. We have wasted 6 billion, why waste 6 or 9 billion more.
WA
When I said `new review board, I meant the `new oversight committee`
WA
I don't think their is any plausible scenario for shutting down Muskrat Falls (short of something catastrophic) so we all need to move on from this dialog.
The announcement yesterday by the Atlantic Premiers bodes well for further distribution of Muskrat Falls energy. http://www.releases.gov.nl.ca/releases/2017/exec/0412n02.aspx
I think this will open up markets in the Eastern US States as well.
Muskrat Falls might not be what any of us wanted but it could have a viable future given free market forces and the sound leadership of Stan Marshall. Remember, Fortis did very well with Stan at the helm. Most boondoggles are usually caused by inept Government mismanagement.
So you are looking to markets in Eastern US States for a cool $1Billion or so annual revenues to make Muskrat and transmission capital costs economically viable.
Good luck
Yeah, Stan will have to be really inventive to sell power, that costs 20 or 30 cents a kilowatt hour to produce, for 5 or 6 cents a kilowatt hour and make money, really innovative, perhaps magical.
#thenewmath
#thingsdonaldtrumpsays
If the North Spur were to fail, you will have a stranded asset, a ruined environment and loss of life downstream, no power for NL, a debt of $12 Billion and counting and a responsibility to provide power to NS! It is disturbing to say the least to hear the opinion of a distinguished commentator such as Mr. Gordon. At the very least, it might be an idea to give some comfort to stakeholders in NL and beyond that the North Spur is stable.
Mike parsons you recommend not having the industry standard independent review and hope the dam does not have a catastrophic failure? and this will save money? Stabilize the site after environmental damages and water quality issues downstream, remediate design and repair.
Shutdown production and face deficits in our Emera contractual commitments?
Some kind of new math all right.
Your justification is Fortis makes a lot of money from assets outside Newfoundland?
Even Commander Spock would find all this amusing.
I think you need to reserve comment for another blog or a facebook page. cape shore memes has some other good comedy.
We should not be accepting the assurances from SNC Lavalin of Quebec in this matter. They are not a well respected company in engineering or in business. We should look to have a review done by credible engineers. Mr. Gordon's advice should be followed in this matter.
Not sure the significance of the fact that SNC has its headquarters n Quebec, James Gordon spent 38 years in Montreal. Would you feel comfortable if they were incompetent but NOT from Quebec? Regardless of their competence or Provincial origin an independent review seems absolutely necessary. By the way, if you have the time and don't yet feel sufficiently spooked, Cabot Martin produced a long but amazingly thorough review of the issues back in 2013.
http://www.nlcpr.com/northspur.pdf
Didn't HQ toss SNC off the Romaine project. Why was that anyway?
We are discussing the North Spur. I think you are on the wrong blog.
The number 13 is unlucky, is that right………I asked my wife. Yes she replied, why do you ask. Yesterday was the thirteenth I explained. Yes but Friday the thirteenth is the worst, yesterday was only Thursday…….what was unlucky about yesterday , she asked.
Well, they dropped the Mother of all bombs, I said. But that was Wednesday she assured me. Oh……Maybe I was wrong.
Well, Mr Gordon confirmed that the North Spur appears unsafe, and needs a Review Panel. I had already mentioned to her, with some pride, that Maurice Adams played an important part in the analysis. I explained….. we have a 12 billion dollar project all at risk. Pretty unlucky I thought.
And yesterday, the thirteenth, The Telegram was sold off, I explained.
My wife made no comment,leaving me to ponder if I was over reacting.
I Googled the Telegram and read: Randy Simms was `shocked at the news…..about the Telegram. Ron Elleworth said it came as a bit of a surprise. Mary Galway thinks it a good thing. That was in relation to the Telegram being sold, not the North Spur, nor the Mother of all Bombs.
A link on the Telegram did show the Telegram yesterday cited a Canadian Press story , on the Mother of all Boombs, and it was on the thirteenth! Right after all…….3 unlucky events.
Now sceptics might question my reliance on the science of things being unlucky. But you can`t much argue with numbers, and 3 unlucky things in one day. Such sceptics would argue against the science of tokens. Tokens, are well documented in Nfld folklore, and can be readily explained.
So there we have it. Surely Uncle Gnarley could have published this piece on Wednesday the 12 th….. enough of bad luck already on Muskrat Madness.
But the Telegram issue…..I ponder if this is luck or unlucky. Heaven knows they did little to expose the folly of Muskrat Madness.
Winston Adams
Mike, I checked out your link….a govn press release.It is an agreement in principle to
1. promote energy efficiency.
2. support technological innovation and cost effectiveness
3. increase efforts to promote energy efficiency, in particular for low income and indigenous communities
4. further electricity the heating and transportation sectors
5 direct their energy ministers to develop an action plan by the summer of 2017 as to climate change.
SO what do you find encouraging for Nfld from any of this given:
1. Nova Scotia is long been tops in promoting energy efficiency in Canada, and Nfld is second worse in the country.
2. Increase efforts to promote energy efficiency ( when you are second worse, and become third worse, it is not impressive, and the increase in effort may be so small as to remain second worse…….where is the targets being mandated!, We saw the HEEEEEEEEEEP program in our budget last week…….good for 100 houses out of 200,000, interest rate of 4.2 percent , and so they take half your savings form energy efficiency in interest charges. Mike, read up on what Nova Scotia does and report back to the readers here
3. further electrify for heating and transportation…..well, resistance (baseboard ) heating is what got us into Muskrat, our winter heating loads are so high due to inefficient electric heating. On the other hand…efficient electric heating (heatpumps) is what Nova Scotia is doing big time (100,000 installed). Here ……no incentives, poor information , and they won`t even provide a list of good manufactures as Nova Scotia has on their website. Lat thing Nfld wants to see is a big move to efficient electric heating…….it reduces revenue and peak demand, counter to the rationale for Muskrat.
As for transportation…….where is the credits for electric cars! Some provinces have provides 8000 dollars for years now.
4 And innovation……I have improved heatpump performance about considerably by mounting the units in the attic. I wanted for Nfld power to let installers know the benefits and how to do it. What do you think their response is………..phone their Conservation Team….Peter Upshall, or Krista……talk to them and report back to the readers here…….they are really excited about this, ….right.
Then inquire about programmable thermostats, and whether they aid peak demand reduction…….and ask why our power , even this time of year jumps up almost 300MW from 3am to 8am. It ain`t toast bread!
6. And I assume you know that all of Muskrat power comes to Soldiers Pond to serve St Johns and the eastern Avalon. This is 55 cent power delivered. Our island 1 cent power gets all shipped to Nova Scotia. There is no winter surplus of Muskrat to go anywhere. 500MW delivered to the Avalon on average, a bit over 700 peak from MW on average to Soldiers pond, not enough for the Avalon in winter when it is cold.
Winston Adams
Thank you Jim for a review of all the engineering done on the north spur and the shortcomings of even the consultants. Nalcor using reports that the author admits to no expertise on quick clay or reports on liquification potential orders of magnitude apart are frightening.
Your analysis makes clear that no comprehensive or competent analysis of failure potential has been done for the north spur. The lies from Nalcor and obfuscation by Stan Marshall go beyond incompetence and are criminal. The risk to downstream people and to the investment are real and are being ignored in the secrecy born of attempts to hide the shady contracts and the local "agents" that greased the wheels. How long will this secrecy be tolerated?
At this point 12 billion is much too conservative an estimate to complete the boondoggle. 15 billion or higher is where we now stand before the inevitable ongoing problems escalate. A pause is essential to clear the air of the stench emanating from Marshal's plan and to do competent engineering studies on the spur.
Can this be allowed to continue with Nalcor's agenda of spending as quickly as possible to get in their view beyond the point of no return? This has resulted in wasteful expensive mistakes and incompetent execution.
Jim you have clearly explained the engineering shortcomings. Overcoming the political resistance to transparent democratic oversight is key to protecting human health and the viability of the NL treasury.
It is a tall order given the irrelevance of the party in power to protect people or the treasury. The feudal overlords and the oligarchs benefiting from this disaster remain above scrutiny. Is there a heroic figure that will stop the madness or will NL slowly fade away with a whimper?
With respect to the potential for liquefaction, and the liquefaction/sensitivity relationship to a soil's Liquidity Index, it seems clear that two separate engineering sources, one of which is fully independent of Nalcor, are in agreement:
One states that in the Lower Clay layer "there are…numerous soil layers, in which the LI exceeds 1.0 – i.e. with values ranging between 1 and 2. In such layers, the water content (w) is significantly higher than the Liquid Limit, (i.e. w >> LL)….(and) … Water contents greater than the Liquid Limit (i.e. w >> LL) manifest the risk of liquefaction or of high sensitivity – … indicating the presence of highly sensitive porous layers … in the Lower Clay Formation."
While the other states that Liquidity Index (LI) "Values in excess of 1 are an indication of the potential for both liquefaction and flow type failures".
These two separate engineering positions appear to be in substantial agreement —i.e., where there are Liquidity Index values above 1, there is a potential for liquefaction.
Yet, SNC-Lavelin/Nalcor's Dec. 2015 Progressive Failure Report states that "even if there were a first time failure in this (Lower Clay) unit, there would not be retrogression and flowslide".
How can SNC-Lavelin/Nalcor's 2015 statement be correct?
In 1985-1986 I worked on the construction of a 26km stretch of road from Cartwright,Labrador to a site slated for construction of a radar site SE of Cartwright; part of the DEW line.
At approximately 12 km from Cartwright the road crossed what is known as Dyke's river; the crossing consisted of rock fill extending into the river on both sides of the river with a Bailey bridge joining the rock fill in the centre of the river.
During placement of rock fill for the West abutment a dozer (TD-25 which is similar to a D-6 for comparison purposes) was submerged in the river as the crust of the riverbed broke through; the rock fill pad which the dozer was travelling on as it pushed rock fill into the river working dropped due to the combined weight of the rock fill and dozer; with additional weight of the rock trucks delivering the rock.
After this event it became mandatory to lower small bags of explosives along the leading edges of the newly placed rock fill; when detonated the river bed crust would rupture and the newly placed rock fill would drop through this crust and gain footing on a firmer bottom.
As Cartwright and Muskarat Falls are basically on opposite end of Lake Melville it is conceivable both sites are setting on the same geology. Just hoping NALCOR and all these engineering companies are basing their faith in the North Spur on actual field tested results and not computer generated models.
As seem from a small road construction the river bottom crust ruptured and no one was hurt ; just a dozer operator who ended up in the river.
I worked on the Upper Churchill, where many dams were built, some were large, many were small, but even the small ones had soil removed , typically to the bedrock, the bedrock washed, crevices grouted before laying the material for the dam. This was appropriate to assure over time that seepage did not go through cracks and crevices in the rock to eventually cause problems. Many of these did not have much pressure once the water level was raised. It was quality work and on bigger dams attention was paid to the material used and compaction to appropriate standards.
Amazing that Muskrat is being build on mud essentially, will have significant pressure, is susceptable to upstream slides that could generate a pressure wave, or be subjected to minor earth tremors,and documented marine clay in the Spur area, and the Spur itself having slides in the past and yet there is so little concern, as documented by Mr Gordon.
If this is not reviewed by a Review Panel as recommended, it seems those responsible should be liable for criminal charges if there is failure of this dam. Cannot understand why people in authority are failing to act in responsible manner. Consultants are given mandates that limit their involvement, and take exceptions or caveats to arrive at a proper assessment, and want to cover their ass as to liability. Shocking. The public should not risk having a major inquiry after a failure and likely loss of life, and a 12 billion asset wasted. Assurance that failure will not occur is necessary. At present there is no reasonable assurance.
The PUB has washed their hands on this….they have no authority they say. Unbelievable this can happen in Canada. Not surprising it can happen in Nfld and Labrador.
Winston Adams
The most shocking event was that mentioned by Gordon in the past: that when drilling in the North Spur, when the vibrating drill stopped for a while by the operator, the drill casing dropped some 20 ft under its own weight into the mud that was part of the make up of the Spur……..so really good material there to depend on……..this was reported by the guy doing the drilling, but was sort of hidden in the records.
PF
See we have a new shriff in town, owners of the Telegram. Will we have Joe Friday as of the Naked City…….`just the facts mam` or more of the same old, same old……..no real investigative journalism. Likely worse than before.
I wonder how much worse it can get! Russel, Wang Bam Thank You Mam, just did another hit piece on Justin Brake "breaking the law" and deserving prosecution for following a story into the Nalcor site.
There is zero chance Russel or the other Nalcor propagandists like Ashley will ever do any investigation on the Muskrat madness. They mouth the Nalcor lie of the day faithfully, uncritically, without conscience or professional respect. Russel boldly coming out against press freedom tells us all we need to know about the new boss, same as the old boss (if I can quote the Who).
The traditional media, looking over their shoulders and trembling in fear, are afraid to do any investigation that threatens the status quo. It is only blogs like this that provide a voice to contrary views and do analysis, are what the Fourth Estate should be about. The impotent, like Russel, will keep bashing real journalists who make them uncomfortable reminding them what they should be doing. Off to the gulag for Justin!
You are right on Bruno….Russell would oppose Gandhi's march to the coast to defy the British laws on Salt………..even if laws are unjust, obey them, and if journalists step over the line, throw them in jail………he sees no special right for journalists, constitutional or otherwise……….what about upholding peace and safety…………his footage of RCMP and Innu in civil discussion documents that, and maybe it would be different is Blake was not there.
I guess Russell would want legal opinions before taking such risk, and the opinion would be stay away, we will accept what the authorities tell us and we will report that.
Russell did not say if Blake should be convicted, has Russell sent a donation to his cause……..the legal defense………..
I guess Russell knows what side his bread is buttered on……….and now taking direction from Mark Lever, the new owner.