Volume 20, Issue 1 (March 1997)
Measurement of Volume Changes in Triaxial Tests Using Digital Imaging Techniques
Conventional procedures for the determination of volume changes in triaxial tests are based on the amount of pore fluid changes into or out of the fully saturated cylindrical specimen. As a triaxial soil specimen shears, the total volume may increase or decrease depending on the soil density, current state of stress, and the stress history. The measurement of these changes in volume are of great importance in the characterization of the soil's mechanical properties. This paper presents an innovative or alternative technique that has been used for measuring the volumetric deformation that cylindrical specimens experience during the shearing stages of a triaxial test. This method incorporates digital imaging techniques and computer-aided analysis to assess the changes in volume throughout a test. A detailed description of the hardware and other equipment is provided along with the data analysis methodology used to simplify the operation. Comparisons are made between the observed results and those obtained from conventional measurement techniques.