Automated true triaxial apparatus development for soil mechanics investigation

Soil mechanical fully understanding requires considering a three dimensional approach, including soil response under the second principal stress and its potential anisotropy. In order to achieve such soil mechanical understanding, a true triaxial apparatus might be used. Therefore, in the present research an automated true triaxial apparatus was developed comprising its cubical cell, data acquisition and stress control systems. The manufactured apparatus was validated by means a laboratory test campaign where true triaxial test responses were compared to standard drained triaxial tests. True triaxial and standard drained triaxial tests were carried out on both naturally and artificially cemented soils. Results were gathered and compared. A soil mechanical compatibility was observed when test results of the newest true triaxial equipment were compared to test results obtained from a well validated standard triaxial apparatus. Thereby, the present paper reports an affordable successful true triaxial apparatus development demonstrating its efficiency for regular soil mechanical tests. Finally, a full stress rosette was established for a uniform fine sand where some small anisotropy was detected.