question: In your example, you used the moist unit weight of 110 pcf to calculate the total stress at 10 feet. Sometimes I have seen examples where both dry and moist unit wights are given or dry unit weight and % moisture are given. One solution in one problem uses the dry unit weight to calculate total stress. In a similar problem elsewhere the author uses the moist unit weight to calculate the total stress without an explanation why. If you had a problem with both dry and moist unit weight for a layer given, which one would you use to calculation both total and effective stresses? I believe moist unit weight makes more sense since soils are hardly dry from practical point of view.
thanks for contributing the helpful re-sources free for us,In India coaching institutes loot millions of money from students for this kind of information.
34:53, u20 and u60 cannot be computed like that as the seepage contribution cannot be determined by using the GWL head and Piezo head as a datum respectively. There are only two points to determine the PWP u10 and u50.
The computation of pore pressures (Pp) seems to be incorrect. This is what I think: - at depht 10: Pp10=0 - at depht 50: Pp50= 60x62.4=3744 (using the piezometer) As pore pressure behave linearly, the slope is (3744-0)/(50-10)=93.6 Therefore, - at depht z, Pp(z)=93.6(z-10). It gives: Pp10=0 Pp20= 93.6x(20-10)=936 Pp50=93.6(50-10)=3744 Pp60= 4680.
Don’t think your graphical representation of pore water pressure at 25:63 is right. Shouln’t you account the depth h in your triangle? Please correct me if I missed something, thanks!
I have a question at 34:51 why didnt you put piezometer at 20' below ground to determine the water rise and calculate the porewater pressure? is it just 10 x 62.4? tnx Godbless
because half (10') of the sand soil is dry and only half (10') is saturated. and we know to calculate pore pressure, we need only need the height of saturated soil. hope that helps. in other words u use the height of the ground water table.
The lecture is nice but the definition or the expression to describe the effective stress as the contact to contact stress of particles is incorrect. The effective stress is a fictitious stress (not real stress) equal to the force transmitted by soil particles but divided by the total area of the soil cross section.
Ian 21 years experienced structural engineer and never understood the effective pressure properly before this video
Than you 👍
question: In your example, you used the moist unit weight of 110 pcf to calculate the total stress at 10 feet. Sometimes I have seen examples where both dry and moist unit wights are given or dry unit weight and % moisture are given. One solution in one problem uses the dry unit weight to calculate total stress. In a similar problem elsewhere the author uses the moist unit weight to calculate the total stress without an explanation why. If you had a problem with both dry and moist unit weight for a layer given, which one would you use to calculation both total and effective stresses? I believe moist unit weight makes more sense since soils are hardly dry from practical point of view.
thanks for contributing the helpful re-sources free for us,In India coaching institutes loot millions of money from students for this kind of information.
34:53, u20 and u60 cannot be computed like that as the seepage contribution cannot be determined by using the GWL head and Piezo head as a datum respectively. There are only two points to determine the PWP u10 and u50.
one of the best channel for Civil Engineer!!. Thank you professor!. Can you also add lesson for slope stability?
The computation of pore pressures (Pp) seems to be incorrect.
This is what I think:
- at depht 10: Pp10=0
- at depht 50: Pp50= 60x62.4=3744 (using the piezometer)
As pore pressure behave linearly, the slope is (3744-0)/(50-10)=93.6
Therefore,
- at depht z, Pp(z)=93.6(z-10).
It gives:
Pp10=0
Pp20= 93.6x(20-10)=936
Pp50=93.6(50-10)=3744
Pp60= 4680.
SOMEONE ANSWER THIS.
So effective stress isn’t affected but depth of surfsce water? I thought if we lower groundwater table then effective stress decreases
Excellent lecture, thx!
True
That was great explanation. Thank you .
does the piezometer have to be at a specific depth?
Step by step video solutions of civil engineering questions
Don’t think your graphical representation of pore water pressure at 25:63 is right. Shouln’t you account the depth h in your triangle? Please correct me if I missed something, thanks!
What a Great Class!
What if you wanna get the more water pressure at C but you dont have a piezometer how will you find it?
Thank you sir .it's amazing axplanation
I have a question at 34:51 why didnt you put piezometer at 20' below ground to determine the water rise and calculate the porewater pressure? is it just 10 x 62.4? tnx Godbless
i have the same doubt
why is the piezometer indicates only the pore pressure has if there is only water in the tank ? (dosent the soil makes it diferent ? )
Sir plzzz add more as more lecture possible ...
Plzzzz......
Thank you sir!! Good lecture!!
Very well explained. Thank you.
Marvelous
In the calculation of pore water pressure down at 20', why is it used 10' but not 30'?
because half (10') of the sand soil is dry and only half (10') is saturated. and we know to calculate pore pressure, we need only need the height of saturated soil.
hope that helps. in other words u use the height of the ground water table.
@@steebay if we use bernoulli then it gives 30'
Very nice video sir!
Very useful, thank you so much
many thanks from egypt
Mind blowing lecture sir
How can i take a matirial plz
Amazing video and amazing explanation. Thank you so much Dr. Franke. This will help me in my thesis defense !
视频很好，谢谢！
wow that was helpfull......now i love this subject😂
Mind blowing :)
Good
Thank you! Help a lot :)
Thank you. I love Geotech!
Thank you Sir
25:40
bless you sir
What's your reference in this lecture sir?
Clinton Ordeniza "karun pa ko maglantaw" hindi mo kami malolokoooo
@@asmb1234 na-view na nako ni nga vid before pa gahatag si ma'am hahaha
parang braja das xD
tew gewd!
The lecture is nice but the definition or the expression to describe the effective stress as the contact to contact stress of particles is incorrect. The effective stress is a fictitious stress (not real stress) equal to the force transmitted by soil particles but divided by the total area of the soil cross section.
12.21
Shout sa mga classmate ko sa 132 - moyaks
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hatag summary hehe
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