CEEN 641 - Lecture 11 - PQ Diagrams and Stress Paths
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- Опубліковано 21 чер 2024
- This video introduces the topic of pq diagrams and stress paths for representing stress loading of soils. Both total and effective stress paths are discussed. The significance of the stress path direction is explained.
Very good video. I’m in a graduate geotech class and a lot of these concepts are bit rusty for me. You explain it all in a very concise and thorough way that is understandable.
I'm loving your lectures. Thank you for making them available.
A point of clarification; in this lecture p' is defined as (sig1+sig3)/2, which, I believe, is the MIT definition and we in Australia tend to call s-t plots rather than p-q plots. In your CSSM lectures you have used the Cambridge definition of p', namely (sig1+sig2+sig3)/3 or (sig1+2*sig3)/3. It may be confusing to some that the slope of the fully drained stress path, for example, is 1:1 in this lecture and 1:3 in your CSSM lectures.
Great information and very well, and clearly, presented. Your students are a privileged bunch!
Brilliant and insightful video. The images are on point! I need to think and let my thoughts consolidate for a while so I CONNECT(in my mind) the OC behaviour in clays/dense sands to the peak behaviour in their shear strength TO the existing stress path . Thank you Professor!
was struggling with understanding the triaxial CU test report, and here comes this video!! Solve my confusion for years, thanks to lecturer for this marvelous course!!!
I really like your lectures. Greetings from Brazil.
wonderful lectures of CSSM, thank you Dr. Franke
very brilliant lecture, thank you so much!
Thank you so much Dr.Franke!
Absolutely amazing
very winderful lecture , I highly appreciated
Thank you. This lecture is really helpful to me for understanding the p-q diagram.
Thank you so much Dr Frankie.
Hey Dr. Kevin,
Thanks for this course. Its really useful. I can see in the playlist that we are missing from lecture 5 to lecture 10. Are they posted somewhere else?
wow! thanks you so much. ❤️❤️❤️
Excellent video! At 19:19 I didnt quite understand why the stress path goes 45 degrees to the right for overconsolidated soils and 45 degrees to the left for normally consolidated soils
Thank you Professor, looking forward more videos about advanced topics to be uploaded. Greeting from Australia!
Thank you!
thanks for the good explanation
so easily delivered
thank you very much sir
Hello Dr. Kevin,
Isn't the modified failure envelope plotting apex of max. mohr circle against center of the max mohr circle called s'-t' plot instead of p'-q'? And the p'-q' plot should be plotting the deviator stress (dia. of the circle) and the average stress.
Also another question @33:02 I always wondered why the stress path for LC is much longer than for AC
Excellent Lecture! Can you make Lectures 5 to 10 and 12 to 13 available?
Very good thank you
Hello my name is Wemerson, excellent work, very good analysis, helped me to understand a little more about Geotechnics, path of tensions, work in a Geotechnics laboratory in Brazil, specialization in geotenia, I like to be studying about it. Are you part of the LinkedIn network? Satisfaction. Congratulations.
Hi Prof. Thank you for your video. I learn a lot from your explanation. May I know which book are you referring to in order to prepare your notes on stress path?
Thank you so much Dr Kevin for your efforts in delivering such productive lectures. You have made this so easy for me to grab these concepts as I really had a hard time getting it.
Hi professor, i have one question.
How does the Mohr-Coulomb failure envelope adjusts to the cases of a axial extension stress path? Are we unable to use the convencional phi and c resistance parameters that we get from the axial compression stress path?
Thank you, i really appreciate the effort that you put in your lectures. Greetings from Perú.
Insightful question! Theoretically, you could use the same Mohr-Coulomb strength parameters you get from ANY of the failure modes because Mohr-Coulomb assumes a linear failure surface. The truth is that the failure surface is non-linear, and measured strength parameters will be slightly different for different mechanisms of loading.
THANKYU
At the 19:06 time on the video you show A-bar = 0.5 as a vertical line. The notes above this state that a soil is contractive to the left and dilative to the right. The O.C. Clay curve is shown going above the K-f line between the A-bar=0.5 and the A-bar=0 lines. However, in the bottom right hand sector of the graph you indicate that if A-bar is
A 0 contractive. Just that
good guy you
Excellent slides on the whole, very informative and detailed. Good explanations throughout. But unfortunately I do not understand your slide on dilative and contractive soils. I think some of what you say are contradictory while other parts have inadequate explanations. I am quite unsure how the stress path of A bar = 0.5 is obtained and how is it straight upwards. I believe that is an effective stress path but I am not sure how change in pore pressure being half of change in deviatoric pressure, sigma vertical-sigma horizontal will net you a vertical line on the p-q graph, it just feels unrealistic
Slay
I think you have mixed the p'-q plot with the s'-t plot.
p' should be 3d all round stress:
take sigma2=sigma3
p'=(sigma1+sigma2+sigma3)/3=(sigma1+2*sigma3)/3
and q should be (sigma1-sigma3)/3+(sigma1-sigma2)/3+(sigma2-sigma3)/3=2/3*(sigma1-sigma3)