Answer: To determine the angle of internal friction (Φ) based on the given data, we can use the following equation.
Explanation:
The following equation is:
tan(Φ) = (σ₁ - σ₃) / (2 * σ₂)
Where:
Φ is the angle of internal friction.
σ₁ is the major principal stress (deviator stress + cell pressure).
σ₃ is the minor principal stress (cell pressure).
σ₂ is the intermediate principal stress (deviator stress).
Given:
Cell Pressure (σ₃) = 150 kPa
Deviator Stress (σ₂) = 490 kPa
Assuming c = 0, which means the cohesion is zero.
Substituting the values into the equation, we get:
tan(Φ) = (σ₁ - σ₃) / (2 * σ₂)
tan(Φ) = (490 - 150) / (2 * 490)
tan(Φ) = 340 / 980
tan(Φ) = 0.3469
To find the angle of internal friction (Φ), we can take the inverse tangent (arctan) of 0.3469:
Φ = arctan(0.3469)
Φ ≈ 19.45°
Therefore, based on the given data and assuming c = 0, the angle of internal friction (Φ) is approximately 19.45°.