1.6. Total Stress Mohr’s Circles

Try these first

1. 1.

   What is the purpose of a triaxial test?

   Hint

   Think about how soil behaves under pressure.

2. 2.

   Name the three types of triaxial tests.

   Hint

   They refer to how the soil is allowed to manage pore water.

3. 3.

   What does a triaxial test aim to determine?

   • Soil density
   • Soil strength
   • Soil permeability

   Hint

   Focus on the purpose of the test.

4. 4.

   True or False: The effective stress is calculated by subtracting pore pressure from total stress.

   • True
   • False

   Hint

   Remember the effective stress formula.

5. 5.

   Given a soil with a cohesion of 5 kPa and an angle of internal friction of 30 degrees, calculate the shear strength at a total normal stress of 100 kPa using the Mohr-Coulomb failure criterion.

   Hint

   Don't forget to convert the angle to radians if using a calculator that requires it.

6. 6.

   Discuss the impact of different pore water pressures on effective stress during a consolidated-undrained test.

   Hint

   Think about how water affects soil structure and strength.