Triaxial Test

The triaxial test is an important method in rock mechanics for determining the strength and deformation characteristics of rock samples. Here's a concise explanation:

Purpose: To measure rock strength and behavior under different confining pressures, simulating underground conditions.

Setup:
  • Cylindrical rock sample
  • Rubber membrane to seal the sample
  • Pressure chamber filled with fluid
  • Axial loading piston
Procedure:
  • Apply confining pressure via fluid in the chamber
  • Increase axial load until sample failure
  • Monitor stress, strain, and volume changes
Key parameters measured:
  • Compressive strength
  • Young's modulus
  • Poisson's ratio
  • Cohesion and friction angle
Types:
  • Conventional: Constant confining pressure
  • True triaxial: Independent control of all principal stresses
Applications:
  • Tunnel design
  • Slope stability analysis
  • Oil and gas reservoir characterization