Automated Triaxial Apparatus for Elevated Pressures
SourceTriaxial testing at elevated pressures has received an increasing amount of attention in recent years, not only for the measurement of design parameters for deep engineering structures, but also to gain a deeper understanding and a complete characterization of the behavior of many natural soils and soft rocks. The paper describes the design of three high pressure triaxial apparatus with capacities between 5 and 70 MPa, each of which is automated for full stress path capability and yet has an emphasis on economy of cost. The apparatus are also designed to measure stiffness from very small strains (0.0001%) to large strains (beyond 10%) over the whole working range of pressures. Examples of data for both soils and soft rocks are used to show the apparatus performance and to highlight the importance of testing over an extended range of pressures.