CEEN 641 - Lecture 11 - PQ Diagrams and Stress Paths

[@davidmychannel7806]

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!

[@teddychan808]

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!!!

[@B27-o2c]

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.

[@marshmelows]

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!

[@lucascruz1518]

I really like your lectures. Greetings from Brazil.

[@johnhwang4365]

Thank you. This lecture is really helpful to me for understanding the p-q diagram.

[@pikxo]

Gracias, una clase magistral 😊

[@hadiasadi3138]

wonderful lectures of CSSM, thank you Dr. Franke

[@jacksonzheng4288]

Thank you Professor, looking forward more videos about advanced topics to be uploaded. Greeting from Australia!

[@reshmarughooputh1609]

Absolutely amazing

[@Y2n123]

Thank you so much Dr Frankie.

[@aymanraouf1820]

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

[@farahbasellinasafira8639]

Thank you so much Dr.Franke!

[@goharalam9870]

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.

[@sangamacharya5715]

very brilliant lecture, thank you so much!

[@TheAncientColossus]

41:30 What do you do AFTER getting the correct stress path according to the field condition?

[@aadilnabiwani2878]

so easily delivered

[@muhamadaminalsalamat9608]

very winderful lecture , I highly appreciated

[@khaledmohamedzahran3473]

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?

[@masyitahmdnujid47]

thanks for the good explanation

[@alandiaz5719]

I have a question. If we have two UU test (or two CU with the same isotropic effective stress) in the lab, and I apply two differents path, for example, one increasing sigma 1 and sigma 3 is constant, and the another one decreasing sigma 3 and sigma 1 constant, the value of qf will be the same? I know that it will be in the Kf line, but i have the quetion because i don't know if it posible that two UU test (the same material and effective stress) can have two values of Su (kpa) due to the path. Thank You!

[@saiedmohammadi]

Very good thank you

[@dccopa13]

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.

[@officehours4028]

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.

[@羅拔迪尼路-n8j]

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.

[@rickycollins40]

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

[@nascasa]

A 0 contractive. Just that

[@wemersonsilvadias4316]

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.

[@Martin-iw1ll]

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

[@shaelmonk-fromont3498]

Excellent Lecture! Can you make Lectures 5 to 10 and 12 to 13 available?

[@kiimiitiruutube2582]

THANKYU

[@aymanraouf1820]

Also another question @33:02 I always wondered why the stress path for LC is much longer than for AC

[@albioncia]

thank you very much sir

[@JamesDean.]

Thank you!

[@civilacademic]

wow! thanks you so much. ❤️❤️❤️

[@lampsgarden]

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?

[@tiggy7777]

good guy you

[@tanarisley5620]

Slay

[@TheAncientColossus]

41:30 What do you do AFTER getting the correct stress path according to the field condition?