The Rock Mechanics and Physics Laboratory (RMPL) undertakes research on the behaviour of rocks and their physical properties specifically for: extraction and storage within the energy sector; understanding of near-surface to shallow crustal earth processes to mitigate the effects of small and large scale geohazards; planning, design and construction within the civil engineering sector.
The RMPL specialises in standard (ISRM and ASTM) and bespoke testing of geomaterials at simulated 0-6km depth conditions (pressure, temperature, pore fluid), including measurement of strength (triaxial and uniaxial), deformability, transport properties (permeability, thermal properties), geophysical properties (elastic wave velocity, acoustic emission…), porosity and density.
Re-created in 2012, the RMPL is the home of BGS’s large scale rock deformation apparatus which is used to measure the physical properties and behaviour of rock when subjected to changes in pressure and temperature associated with near surface to shallow crustal conditions (~6 km). The system comprises an MTS 4.6 MN capacity servo-controlled hydraulic load frame with a versatile capacity for either uniaxial (compression, indirect tensile) or triaxial testing conditions. The triaxial pressure vessel allows for a confining pressure up to 140 MPa (mineral oil confining medium), temperature up to 200 °C and pore pressure up to 100 MPa (using pure water and brine; capacity for inert gas is under development). Synchronous measurement of stress, strain, sonic velocity, acoustic emission (with tomography capacity in development) and permeability during deformation on right-circular cylinder rock samples with the exceptional capacity of diameters ranging from 38 mm up to 100 mm are available depending on the deformation configuration.
Complimentary services available to the laboratory include sample preparation, geotechnical characterisation, thin section preparation and petrological/microstructural analysis.
Research in this laboratory has been used to improve the understanding of material behaviour and processes related to the mechanical and physical properties of rocks, and hence contribute to process models and performance assessment related to CO2 storage, underground gas storage and other underground construction applications. Recent studies have focused on the geomechanical parameters of: reservoir (sandstone) and cap rocks (mudstone) from CCS sites in the North Seas as part of the EPSRC-funded CONTAIN project; underground cavern host rock (halite) for proposed underground compressed air storage as part of the EPSRC-funded IMAGES project and EPSRC CDT EngD on the ‘Impact of impurities and salt structures on environmental risks of H2 storage in salt caverns’; strength and deformability of the Montorfano Granite as part of the SAFER project; and measurement and characterisation of stress induced changes in the electric stress field of geological and man-made materials as part of the EPSRC-funded E-Stress project.