I appreciate the fact that enough knowledge on the subject matter is clearly explained, yet condensed in a video that's just a few minutes long. Good job!
There were some significant landslides / slumps caused by the massive 1964 earthquake in Alaska. Although quick clay has never been blamed for these specifically, as far as I know, Alaska is like Norway in having large amounts of glacial run-off sedimentary deposits which can become quick clay.
The biggest determining factor is the salt content in the clay.......if the salt gets diluted to a certain extent the soil/clay will will liquify If you stir salt into quick clay it will solidify again
As a kid I used to play in the stream with my friend. There was a clay formation on the stream bank just where the stream hit the bank at an angle digging a deep swimming hole. We made a clay slide by moulding it into a slide shape and putting water on it. One day I went down to the slide and there was a huge lake in it's place. The whole side of the hill had slid down and blocked off the stream. It must have been at least 30 feet thick and all the trees were tilting uphill. A massive amount of earth moved. It took a few months for the stream to drain the lake.
I've seen the documentary about the Rissa landslide and it talks about salt being leached out of the quick clay by ground water making it more unstable.
Do people need to have some cores drilled whenever they want to live, work, and build on a mountain side? If it found to have this kind of clay, can anything be injected into it to stabilize it? Sound as chemicals, salt, or concrete mix?
Thanks for your question. Yes, if you want to know if there is quick clay, you need to drill some samples up and get them tested. I think they are working on procedures to avoid physical samples, but testing directly in ground. You can inject stuff to stabilize - but that is inpractical - sine the volume of soil is just too large.
If you are very keen, I recommend you to read this paper: www.ngm2016.com/uploads/2/1/7/9/21790806/ngm2016-021_detecting_quick_clay_with_cptu_valsson.pdf
Since QC is made weaker by the slow removal of salt over time I wonder if all QC deposits are not equally vulnerable. Rissa was just waiting to happen, it seems. Is this right?
👍Very interesting. Thanks. 💝 🤔I have no idea why I’m so interested in this kind of random stuff. But I know I’m on a slippery sliding slope of clicking & watching lots of videos instead of going to bed. 😫
I am led to believe that you are wrong about the causes of Quick Clay slides. The salt content of the clay is vital to the stability of the clay. If the salt content drops, the clay will liquify. Perhaps you have simplified to the point of missing the basic cause.
I think in a Scandinavian context, any quick clay above sea level can be expected to have practically all its salt contents leached away long ago, since it rains so much in our region. So I am guessing that @TheGeotechEngineer had this as an implicit assumption. The question he's answering is therefore "for fully salt-depleted quick-clay, what makes it finally slide?"
Good question. That is too complex to answer - I would need to read too many reports to have a good guess. The top specialist in Norway from NGI and Multiconsult will now be working on this for likely the next 1-2 years before they will have an answer.
@@TheGeotechEngineer According to Wikipedia, construction work using heavy machinery was carried out at the bottom of the location where the landslide took place in November 2020, that is, around one month before the landslide occurred. Furthermore, the authorities had been officially warned about the potential consequences of such construction work, but it went ahead, regardless. Here is an excerpt from Wikipedia : „There have previously been landslides in Gjerdrum municipality. During the night between 20 and 21 October 1924, a landslide destroyed several farms and damaged 1600 metres of road.[3][4][5] In 1973 there was a landslide at Ask.[6] In 1980 there was a landslide that occurred near the south end of the 2020 landslide.[7] In 2014 a landslide destroyed two houses.[8] In July 2008, an article published in Romerikes Blad stated that hydrologist and geologist Steinar Myrabø had warned the municipality of soil erosion and the potential risk of a landslide, calling for a halt in construction at Nystulia on behalf of Norwegian Society for the Conservation of Nature's local chapter.[9] In November 2020, construction, including digging and involving heavy machinery, took place at the bottom of the area where the landslide would take place later next month.[2] According to the broadcaster NRK, intense rain in the days before the incident may have caused soil movements in the area.[10]“
@@TheGeotechEngineer Indeed, it is very sad that it happened, but we must not forget that at least 7 lives have been lost, and the reasons need to found, so that no more innocent people have to pay for other people’s negligence. Also, the answer as to why construction work was carried out against the advice of a hydrologist / geologist needs to be found. I am in no way a geologist or hydrologist, but I can add one and one, and come up with the right answer : 1) it is a historical fact that landslides have taken place in/around Gjerdrum 2) A geologist / hydrologist warned of the possible consequences of construction work in the Nystulia area (death/destruction) 3) The construction work went ahead in November 2020, and the landslide took place in December 2020. I don‘t need a degree in geology to ascertain the probable cause of the landslide : approval of the construction works against expert advice. Innocent people lost their lives and homes due to this negligence, and they must bear the consequences for their decisions which they made against expert advice.
@@zeejimi4044 thanks for your comments. I hope they will find the cause. They have two of the best consultanting companies working on this matter. Local government released 1000 documents today so journalist will likely also be looking in these documents
@@TheGeotechEngineer Well, in some parts of Sweden, Finland and Russia you can find them as well. But that's correct, that they are a huge problem in Norway.
@@TheGeotechEngineer watching The Quake and then The Wave sent me here. Thanks for the informative video! Would you say that The Quake overstates the impact of earthquakes in Norway -if you’ve seen the film?
I appreciate the fact that enough knowledge on the subject matter is clearly explained, yet condensed in a video that's just a few minutes long. Good job!
Hi, I think to become a specialist in this subject likely requires 10 years of working experience... Thanks for the feed back
This is really clear. I watched the 1978 documentary about rissa and then watched this. It made clear. Thanks!
Thanks, i am happy you liked it.
I also watched it along with a friend from South Korea.
There were some significant landslides / slumps caused by the massive 1964 earthquake in Alaska. Although quick clay has never been blamed for these specifically, as far as I know, Alaska is like Norway in having large amounts of glacial run-off sedimentary deposits which can become quick clay.
Heavy rain leeching the salt from the marine clay aka quick clay as happened in Quebec, Canada. Nicely done, Geotech. Thanks.
The biggest determining factor is the salt content in the clay.......if the salt gets diluted to a certain extent the soil/clay will will liquify
If you stir salt into quick clay it will solidify again
Great explanation; thank you
Thanks - i am very glad to hear you liked it.
Thanks!
Geotech from Augusta, GA - keep up the content !
Thanks. I will do my best
As a kid I used to play in the stream with my friend. There was a clay formation on the stream bank just where the stream hit the bank at an angle digging a deep swimming hole. We made a clay slide by moulding it into a slide shape and putting water on it.
One day I went down to the slide and there was a huge lake in it's place. The whole side of the hill had slid down and blocked off the stream. It must have been at least 30 feet thick and all the trees were tilting uphill. A massive amount of earth moved. It took a few months for the stream to drain the lake.
Thanks for your story
I wish I were half as smart and articulate as this RUclipsr! Great video! Constant education and great articulation
Hi, thanks for your feed back.
i am glad I have been able to make more good videos, thanks for all your comments.
I am advanced dummy! Thanks for the upgrade!
I've seen the documentary about the Rissa landslide and it talks about salt being leached out of the quick clay by ground water making it more unstable.
that is true. the salt wash out takes 1000 years… very very slow.
I wonder if drilling cores to check for quick clay can set it off.
I have watched the Rissa quick clay video twice so i am an expert!
Actually, the quick clay slide at Rissa was into a lake, not the ocean.
very good video. Thank you so much!
i am glad you liked it.
There is also a connection to the salt content of quick clay according to a video i watched on the subject.
Amazing nature. Know about clay. Never heard about quick clay.
Neither had i
Do people need to have some cores drilled whenever they want to live, work, and build on a mountain side?
If it found to have this kind of clay, can anything be injected into it to stabilize it? Sound as chemicals, salt, or concrete mix?
Thanks for your question. Yes, if you want to know if there is quick clay, you need to drill some samples up and get them tested. I think they are working on procedures to avoid physical samples, but testing directly in ground.
You can inject stuff to stabilize - but that is inpractical - sine the volume of soil is just too large.
If you are very keen, I recommend you to read this paper: www.ngm2016.com/uploads/2/1/7/9/21790806/ngm2016-021_detecting_quick_clay_with_cptu_valsson.pdf
Tusend takk.
Since QC is made weaker by the slow removal of salt over time I wonder if all QC deposits are not equally vulnerable. Rissa was just waiting to happen, it seems. Is this right?
Flott almendannelse! Takk.
Hei, takk. Jeg jobber med en video på norsk som vil forklare det litt bedre. Jeg håper snart den kommer. Så subscribe gjerne slik du får den med og
👍Very interesting. Thanks. 💝
🤔I have no idea why I’m so interested in this kind of random stuff. But I know I’m on a slippery sliding slope of clicking & watching lots of videos instead of going to bed. 😫
Sleep well ... the videos are there tomorrow.
@@TheGeotechEngineer - 👍Thank you and you’re 100% correct....tomorrow. 😴
We had a bog slide years ago, not sure if it's the same machanics
You can learn a lot from building sandcastles at the beach
Being "an advanced dummy" is all I ever wanted to be! That's just enough to take to my keyboard and get off some good zingers! LOL.
You did not explain what quick clay is and how it becomes more liquid due to salt loss.
What about salt concentration?
I am led to believe that you are wrong about the causes of Quick Clay slides. The salt content of the clay is vital to the stability of the clay. If the salt content drops, the clay will liquify. Perhaps you have simplified to the point of missing the basic cause.
I think in a Scandinavian context, any quick clay above sea level can be expected to have practically all its salt contents leached away long ago, since it rains so much in our region. So I am guessing that @TheGeotechEngineer had this as an implicit assumption. The question he's answering is therefore "for fully salt-depleted quick-clay, what makes it finally slide?"
Cubic is written m3
@TheGeotechEngineer Do you have an opinion about what caused the quick clay at Gjerdrum/Ask to become unstable/fluid ???
Good question. That is too complex to answer - I would need to read too many reports to have a good guess. The top specialist in Norway from NGI and Multiconsult will now be working on this for likely the next 1-2 years before they will have an answer.
@@TheGeotechEngineer According to Wikipedia, construction work using heavy machinery was carried out at the bottom of the location where the landslide took place in November 2020, that is, around one month before the landslide occurred. Furthermore, the authorities had been officially warned about the potential consequences of such construction work, but it went ahead, regardless.
Here is an excerpt from Wikipedia : „There have previously been landslides in Gjerdrum municipality. During the night between 20 and 21 October 1924, a landslide destroyed several farms and damaged 1600 metres of road.[3][4][5] In 1973 there was a landslide at Ask.[6] In 1980 there was a landslide that occurred near the south end of the 2020 landslide.[7] In 2014 a landslide destroyed two houses.[8]
In July 2008, an article published in Romerikes Blad stated that hydrologist and geologist Steinar Myrabø had warned the municipality of soil erosion and the potential risk of a landslide, calling for a halt in construction at Nystulia on behalf of Norwegian Society for the Conservation of Nature's local chapter.[9] In November 2020, construction, including digging and involving heavy machinery, took place at the bottom of the area where the landslide would take place later next month.[2] According to the broadcaster NRK, intense rain in the days before the incident may have caused soil movements in the area.[10]“
@@zeejimi4044 the team worikng on this will likely find the reason, or maybe there are more reasons. Regardless it is truely sad that it happend.
@@TheGeotechEngineer Indeed, it is very sad that it happened, but we must not forget that at least 7 lives have been lost, and the reasons need to found, so that no more innocent people have to pay for other people’s negligence. Also, the answer as to why construction work was carried out against the advice of a hydrologist / geologist needs to be found. I am in no way a geologist or hydrologist, but I can add one and one, and come up with the right answer : 1) it is a historical fact that landslides have taken place in/around Gjerdrum 2) A geologist / hydrologist warned of the possible consequences of construction work in the Nystulia area (death/destruction) 3) The construction work went ahead in November 2020, and the landslide took place in December 2020.
I don‘t need a degree in geology to ascertain the probable cause of the landslide : approval of the construction works against expert advice. Innocent people lost their lives and homes due to this negligence, and they must bear the consequences for their decisions which they made against expert advice.
@@zeejimi4044 thanks for your comments. I hope they will find the cause. They have two of the best consultanting companies working on this matter. Local government released 1000 documents today so journalist will likely also be looking in these documents
You forgot earthquakes as one of the triggers.
Thanks for your comment. That is likely true - but there are hardly any earth quakes in Norway. So rather unlikely.
@@TheGeotechEngineer I thought you were explaining quick clay landslides in general, not only in Norway.
Thanks.
Hi, thanks for your comment. That is a fair point. quick clay is nearly only found in Norway and Canada.
@@TheGeotechEngineer Well, in some parts of Sweden, Finland and Russia you can find them as well. But that's correct, that they are a huge problem in Norway.
@@TheGeotechEngineer watching The Quake and then The Wave sent me here. Thanks for the informative video! Would you say that The Quake overstates the impact of earthquakes in Norway -if you’ve seen the film?
Utmerket på engelsk også
takk for tips
Hej alihoopan.
Hej hej