Large Scale Polyaxial Equipment
RPS-600 Large Scale Polyaxial Rock Testing System

The GCTS RPS-600 Large Scale Polyaxial (True Triaxial) Rock Testing System has been expertly crafted to examine the intermediate principal stress effect on rock engineering behavior and thus adequately describe the strength of rock under a general system. This is done through professional design and engineering to bring the most precise results possible.


  • Test cubical 300 mm x 300 mm by 600 mm tall rock specimens (12”x 12”x 24”).
  • Perform Polyaxial (true triaxial) tests.
  • Independent control of σ1, σ2, σ3 (where σ1≠σ2≠σ3) or e1, e2, e3 or a combination of stress or strain control for each axis.
  • Measures strains in all three orthogonal directions.
  • Optional pore pressure control up to 140 MPa.
  • Available ultrasonic sensors to measure P and S wave velocities under different stress states.
  • Optional hydraulic fracturing platens available to perform wellbore stability tests.
  • Stainless steel construction.
  • Optional temperature control up to 200 °C.

The GCTS RPS-600 Polyaxial Rock Testing system 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 RPS-600 is designed to apply 3 independent stresses (σ1, σ2 and σ3) onto a cubical test specimen. The stresses are achieved through hydraulic intensifiers applying pressure to solid platens in contact with the specimen. The system can be upgraded with pore pressure and temperature control.


GCTS also offers hydraulic fracturing fixtures to approximate the effects of anisotropic stress state on borehole stability. 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.


  • 300 mm x 300 mm x 600 mm maximum specimen size
  • 100 MPa stress capacity
  • 140 MPa confining pressure capacity
  • Temperature control to 200°C
  • 18 total loading plates
  • 16 electrical feed-through lines


Please contact GCTS for full specifications.