Griggs Apparatus x 3

Griggs Apparatus

Brown University

The Brown Rock Mechanics lab houses three Griggs-type deformation apparatus These apparatus operate at pressures up to 2.0 GPa and temperatures up to 1400˚C (1200˚C easily). Experiments can be conducted at strain rates from 5e-4/s to 1e-9/s (with a practical limit of around 3e-8/s). Over the last several years, these apparatus have been updated to allow monitoring of acoustic emissions, drainage of pore fluids, constant stress creep tests, and frictional experiments with variable rig stiffness. Stress measurements are made with practical resolution of ~10 MPa. Samples sizes are approximately 12.5 mm in length with a diameter of 6.25 mm. Experiments can be done in both axial compression and general shear (with shear strains up to ~6 to 7).

Loading; Unloading