Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
(OP)
Which should be our failure criterion
(Sigma1- Sigma3)max or
(Sigma1/Sigma3)max
they do not coincide when having undrained case
Please refeer me to specialized paperes or texts if you can





RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
f-d
¡papá gordo ain’t no madre flaca!
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
Sorry for any confusion.
f-d
¡papá gordo ain’t no madre flaca!
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
Soildynamics - You should explain what you are using the results for and what the stress-strain curve and effective-stress path look like. Otherwise, people here can't really be very helpful. The answers to these questions are very often context-dependent.
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
“Five different criteria of “failure”, from which the shear strength of a soil is determined are . . .
• Peak Deviator Stress
• Maximum principal stress ratio
• Limiting Strain
• Critical State
• Residual State
“(1) Maximum Deviator Stress
The maximum or ‘peak’ deviator stress criterion is the one that is traditionally associated with ‘failure’ in the testing of soil samples. . . . If the vertical and horizontal principal stresses are denoted by s1 and s3, the peak deviator stress is written (s1 - s3)f and the corresponding strain is denoted by ef. In an undrained test the pore pressure at that strain is denoted by uf, from which the principal effect stresses at peak can calculated. . . .
“(2) Maximum Principal Stress Ratio
If the principal effect stresses s1’ and s3’ are calculated for each set of readings taken during an undrained test, values of the principal stress ratio s1’ / s3’ can be calculated and plotted against strain. . . .The ratio is equal to 1 at the start of the test because at that point s1 = s3, and therefore s’1 = s3’. The maximum value of the ratio occurs at about the same strain as the peak deviator stress in many undrained tests on normally consolidated clays.
“The maximum stress ratio criterion . . . is preferable to the peak stress criterion in some ways because it can provide a better correlation of shear strength with other parameters, or between different types of test. It is particularly useful for clays in which the deviator stress continues to increase at large strains. It can also be used as a criterion in multistage undrained triaxial tests.
“The stress ratio is not used for drained tests, except perhaps to quote the value at ‘peak’ deviator stress, because the effective stress changes are equal to the total stresses changes, and the stress ratio curve is the same shape as the deviator stress plot.”
Sorry for the long post, but I thought this was a good and clear explanation.
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
it is valuable stuff.
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
RE: Failure Criterion: (Sigma1- Sigma3)max Vs (Sigma1/Sigma3)max
You are the contrary one.