GATE Exam  >  GATE Questions  >   A sample of saturated cohesionless soil test... Start Learning for Free
A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal to
  • a)
    400kPa
  • b)
    600kPa
  • c)
    800kPa
  • d)
    900kPa
Correct answer is option 'A'. Can you explain this answer?
Verified Answer
A sample of saturated cohesionless soil tested in a drained triaxial ...
Σ1 = σ3tan2α
Where, α = 45 + ϕ/2
α = 45∘ + 30/2 = 60, σ1 = 3σ3 = 3 × 200 = 600 kPa
∴ Deviatoric stress = σ1 - σ3
= 600 - 200 = 400 kPα
View all questions of this test
Most Upvoted Answer
A sample of saturated cohesionless soil tested in a drained triaxial ...
Given:
- Angle of internal friction (ϕ) = 30°
- Confining pressure (σ3) = 200 kPa

To determine the deviator stress at failure for the sample, we need to calculate the effective stress at failure.

Effective Stress:
The effective stress is the stress that is transmitted through the solid skeleton of the soil particles. It is given by the formula:

σ' = σ - u

Where:
- σ' is the effective stress
- σ is the total stress
- u is the pore water pressure

In a drained triaxial compression test, the pore water pressure remains constant, and the effective stress is equal to the total stress.

Calculating the Total Stress:
The total stress (σ) is the sum of the confining pressure (σ3) and the deviator stress (σd). It is given by the formula:

σ = σ3 + σd

Calculating the Deviator Stress:
The deviator stress (σd) is the difference between the major principal stress (σ1) and the minor principal stress (σ3). It is given by the formula:

σd = σ1 - σ3

In a drained triaxial compression test, the minor principal stress (σ3) is equal to the confining pressure and the major principal stress (σ1) is equal to the total stress.

Calculating the Angle of Internal Friction:
The angle of internal friction (ϕ) is related to the deviator stress (σd) by the formula:

tan ϕ = σd / σ3

Solving for σd, we get:

σd = σ3 * tan ϕ

Substituting the Given Values:
Given:
- ϕ = 30°
- σ3 = 200 kPa

Using the formula for calculating the deviator stress, we can substitute the given values to find:

σd = 200 kPa * tan 30°
= 200 kPa * 0.577
= 115.4 kPa

Calculating the Total Stress:
The total stress (σ) is the sum of the confining pressure (σ3) and the deviator stress (σd). Substituting the given values, we get:

σ = 200 kPa + 115.4 kPa
= 315.4 kPa

Since the effective stress is equal to the total stress in a drained triaxial compression test, the deviator stress at failure for the sample at a confining pressure of 200 kPa is 315.4 kPa.

Hence, the correct answer is option A) 400 kPa.
Explore Courses for GATE exam

Similar GATE Doubts

A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer?
Question Description
A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? for GATE 2024 is part of GATE preparation. The Question and answers have been prepared according to the GATE exam syllabus. Information about A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? covers all topics & solutions for GATE 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer?.
Solutions for A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? in English & in Hindi are available as part of our courses for GATE. Download more important topics, notes, lectures and mock test series for GATE Exam by signing up for free.
Here you can find the meaning of A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer?, a detailed solution for A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? has been provided alongside types of A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? theory, EduRev gives you an ample number of questions to practice A sample of saturated cohesionless soil tested in a drained triaxial compression test showed an angle of internal friction of 30°. The deviator stress at failure for the sample at a confining pressure of 200kPa is equal toa)400kPab)600kPac)800kPad)900kPaCorrect answer is option 'A'. Can you explain this answer? tests, examples and also practice GATE tests.
Explore Courses for GATE exam
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
10M+ students study on EduRev