The GCTS RPX-150 Polyaxial fixture can be used to study the intermediate principal stress effect on rock engineering behavior and describe adequately the strength of rock under a general system of Polyaxial compressive stresses.
The RPX-150 is a simple and economical fixture that enhances the capabilities of standard GCTS Rock Triaxial systems that includes both, cell and pore pressure control. This fixture is designed to fit inside GCTS triaxial cells and use the load frame to (typically) apply σ1, the cell pressure to apply σ2 and the pore pressure system to apply σ3 through the fixture’s flat jacks.
GCTS also offer semi-circular platens to test cylindrical specimens together with GCTS hydraulic fracturing fixtures and approximate the effects of anisotropic stress state on borehole stability. Even though the stress state applied with these semicircular loading jacks is not uniform, it is much easier to prepare and test cylindrical specimens. Ultrasonic sensors can also be provided to study the effects anisotropic stress conditions on compression and shear wave velocities. Velocities for all three axes can easily be measured during Polyaxial tests with this option.