THE TRANSPARENT LAB

Micro-CT: Phoenix v|tome|x micro-CT

Phoenix v|tome|x micro-CT is a versatile high-resolution system for 2D X-ray and 2D computed tomography, equipped with an open directional high-power microfocus X-ray tube. The Phoenix v|tome|x is capable of generating images with voxel size down to 5 microns and a maximum 3D scanning sample size up to 260mm x 420mm (diameter x height) and 10 kilograms. 6-axes (x, y, z, rotation, tilt, and detector shift) CNC provides accurate and stable sample positioning that gives reproducible precision 2D and 3D imaging.

Zhao, Q., Glaser, S. D., Tisato, N., & Grasselli, G. (2020). Assessing Energy Budget of Laboratory Fault Slip Using Rotary Shear Experiments and Micro-Computed Tomography. Geophysical Research Letters, 47(1). Cite
Abdelaziz, A., Ha, J., Abul Khair, H., Adams, M., Tan, C. P., Musa, I. H., & Grasselli, G. (2019). Unconventional Shale Hydraulic Fracturing Under True Triaxial Laboratory Conditions, the Value of Understanding Your Reservoir (p. 16). Presented at the SPE Annual Technical Conference and Exhibition - ATCE 2019, SPE: Society of Petroleum Engineers. Cite
Zhao, Q., Glaser, S. D., Tisato, N., & Grasselli, G. (2019). Assessing Energy Budget of Laboratory Fault Slip Using Quantitative Micro-CT Image Analysis (p. 6). Presented at the 53rd U.S. Rock Mechanics/Geomechanics Symposium, ARMA: American Rock Mechanics Association (ARMA). Cite
Zhao, Q., Tisato, N., Kovaleva, O., & Grasselli, G. (2018). Direct Observation of Faulting by Means of Rotary Shear Tests Under X-Ray Micro-Computed Tomography. Journal of Geophysical Research-Solid Earth, 123(9), 7389–7403. Cite
Zhao, Q., Tisato, N., & Grasselli, G. (2018). Rotary shear test under X-ray micro-computed tomography. Presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, Seattle: American Rock Mechanics Association (ARMA). Cite
Kalogerakis, G. C., Zhao, Q., Grasselli, G., & Sleep, B. E. (2018). In situ chemical oxidation processes: 4D quantitative visualization of byproduct formation and deposition via micro-CT imaging. The Leading Edge, 37(6), 462–467. Cite
Zhao, Q., Tisato, N., & Grasselli, G. (2017). Rotary shear experiments under X-ray micro-computed tomography. The Review of Scientific Instruments, 88(1), 015110. Cite
Ha, J. (2017). FDEM Tunnel Modelling in Georgian Bay Shale (MASc Thesis). University of Toronto. Cite
Tisato, N., Zhao, Q., & Grasselli, G. (2016). Experimental rock physics under micro-CT. In C. Sicking & J. FergusonSicking (Eds.), SEG Technical Program Expanded Abstracts (Vol. 35, pp. 3251–3255). Presented at the SEG International Exposition and 86th Annual Meeting, SEG 2016, Dallas, Texas: Society of Exploration Geophysicists.Scopus. Cite
Tisato, N., Zhao, Q., & Grasselli, G. (2016). Experimental rock deformation under micro-CT - Two new apparatuses for rock physics. In C. Kuwait Petroleum, Subsidiaries, Omv, A. Saudi, & Shell (Eds.), 78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking Potential. Presented at the 78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking Potential, Vienna, Austria.: European Association of Geoscientists and Engineers, EAGE.Scopus. Cite
Tisato, N., Chapman, S., Zhao, Q., Grasselli, G., & Quintal, B. (2015). Seismic wave attenuation in rocks saturated with bubbly liquids: Experiments and numerical modeling. In R. V. Schneider (Ed.), SEG Technical Program Expanded Abstracts (Vol. 34, pp. 3254–3258). Presented at the SEG New Orleans Annual Meeting, SEG 2015, New Orleans, Louisiana: Society of Exploration Geophysicists.Scopus. Cite
Tatone, B. S. A., & Grasselli, G. (2015). A combined experimental (micro-CT) and numerical (FDEM) methodology to study rock joint asperities subjected to direct shear. 49th U.S. Rock Mechanics / Geomechanics Symposium 2015 (Vol. 1, pp. 38–47). Presented at the 49th U.S. Rock Mechanics/Geomechanics Symposium, San Francisco, California: American Rock Mechanics Association (ARMA).Scopus. Cite
Tatone, B. S. A., & Grasselli, G. (2014). Characterization of the effect of normal load on the discontinuity morphology in direct shear specimens using X-ray micro-CT. Acta Geotechnica, 10(1), 31–54.Scopus. Cite
Mahabadi, O. K., Tatone, B. S. A., & Grasselli, G. (2014). Influence of microscale heterogeneity and microstructure on the tensile behavior of crystalline rocks. Journal of Geophysical Research: Solid Earth, 119(7), 5324–5341.Scopus. Cite

Experimental Rock Deformation Physics: ERDμ-Q and ERDμ-T

Used in the measurement of seismic wave attenuation, the X-Ray transparent ERDμ-Q vessel is used in conjunction with a micro-CT machine for continuous imaging. The vessel is able to apply confining pressures up to 30 MPa and pore pressures up to 20 MPa with varying fluids for a 12 x 36 mm cylindrical sample. The vessel applies a sinusoidal variation of the vertical stress, and with an axial load cell and a cantilever system quantifies a complex Young’s modulus of the specimen to derive the seismic attenuation for a given material.

Similar to the ERDμ-Q, the ERDμ-T vessel can be used to observe rotary shear effects on a slipping surface with a micro-CT imaging machine for continuous imaging during rotary shear deformation. The rate of rotary shear varies from 0.8 to 48mm/s. The ERDμ-T vessel is also able to generate confining pressures up to 30 MPa, for a sample size of 12 x 36 mm. Being able to image the 4D progression of slipping mechanics and the slip surface characteristics, the ERDμ-T provides new capabilities to understand gauge layers on rock friction during shear mechanisms.

Zhao, Q., Glaser, S. D., Tisato, N., & Grasselli, G. (2020). Assessing Energy Budget of Laboratory Fault Slip Using Rotary Shear Experiments and Micro-Computed Tomography. Geophysical Research Letters, 47(1). Cite
Zhao, Q., Glaser, S. D., Tisato, N., & Grasselli, G. (2019). Assessing Energy Budget of Laboratory Fault Slip Using Quantitative Micro-CT Image Analysis (p. 6). Presented at the 53rd U.S. Rock Mechanics/Geomechanics Symposium, ARMA: American Rock Mechanics Association (ARMA). Cite
Zhao, Q., Tisato, N., Kovaleva, O., & Grasselli, G. (2018). Direct Observation of Faulting by Means of Rotary Shear Tests Under X-Ray Micro-Computed Tomography. Journal of Geophysical Research-Solid Earth, 123(9), 7389–7403. Cite
Zhao, Q., Tisato, N., & Grasselli, G. (2018). Rotary shear test under X-ray micro-computed tomography. Presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, Seattle: American Rock Mechanics Association (ARMA). Cite
Zhao, Q., Tisato, N., & Grasselli, G. (2017). Rotary shear experiments under X-ray micro-computed tomography. The Review of Scientific Instruments, 88(1), 015110. Cite
Tisato, N., Zhao, Q., & Grasselli, G. (2016). Experimental rock physics under micro-CT. In C. Sicking & J. FergusonSicking (Eds.), SEG Technical Program Expanded Abstracts (Vol. 35, pp. 3251–3255). Presented at the SEG International Exposition and 86th Annual Meeting, SEG 2016, Dallas, Texas: Society of Exploration Geophysicists.Scopus. Cite
Tisato, N., Zhao, Q., & Grasselli, G. (2016). Experimental rock deformation under micro-CT - Two new apparatuses for rock physics. In C. Kuwait Petroleum, Subsidiaries, Omv, A. Saudi, & Shell (Eds.), 78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking Potential. Presented at the 78th EAGE Conference and Exhibition 2016: Efficient Use of Technology - Unlocking Potential, Vienna, Austria.: European Association of Geoscientists and Engineers, EAGE.Scopus. Cite
Tisato, N., Chapman, S., Zhao, Q., Grasselli, G., & Quintal, B. (2015). Seismic wave attenuation in rocks saturated with bubbly liquids: Experiments and numerical modeling. In R. V. Schneider (Ed.), SEG Technical Program Expanded Abstracts (Vol. 34, pp. 3254–3258). Presented at the SEG New Orleans Annual Meeting, SEG 2015, New Orleans, Louisiana: Society of Exploration Geophysicists.Scopus. Cite

Material Charactierization: Nanovea Micro- and Nano-Indenter

The Nanovea Micro- and Nano- Material testing modules gauge material properties through indentation and scratch testing on varying scales. Micro and Nano indentation modules can assess material hardness, elastic modulus, fracture toughness and yield strength. The microindenter module are used with sphereconical and Vickers tips while the nanoindentation module are available in the Berkovich tip.

Ay, B., Parolia, K., Liddell, R. S., Qiu, Y., Grasselli, G., Cooper, D. M. L., & Davies, J. E. (2020). Hyperglycemia compromises Rat Cortical Bone by Increasing Osteocyte Lacunar Density and Decreasing Vascular Canal Volume. Communications Biology, 3(1), 20. Cite
Qiu, Y., Abdelaziz, A., Peterson, K., & Grasselli, G. (2018). Modelling of concrete weight coating based on micromechanical characterization. Presented at the RILEMweek/CONMOD, Delft Netherlands. Cite
Qiu, Y., Peterson, K., Grasselli, G., Moslow, T., & Adams, M. (2018). Micromechanical characterization of the lower Triassic Montney Claraia biostrome. Presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, Seattle. Cite

Multi-scale Surface Scanning: ATOS II 3D Surface Scanner

ATOS uses advance measuring and projection techniques to produce high quality data and precision accuracy for full-object dimensional analysis. It can measure shiny surfaces and complex component with pocket and/or fine edges. 3 high quality optical cameras capable of 16 million points per scan (PPS) work independently for maximum data collection and minimum number of scan, thereby reducing overall measurement time. Narrow band blue light technology improves the scanning of dark or coloured surfaces, also enables precise measurements to be carried out independently of environmental lighting conditions, thereby reduces heat development. Interchangeable measuring volumes and various configurations allow for project versatility.

Magsipoc, E., Zhao, Q., & Grasselli, G. (2019). 2D and 3D Roughness Characterization. Rock Mechanics and Rock Engineering. Cite
Magsipoc, E. (2019). Quantifying the Fracture Process using Surface Roughness Parameters (MASc Thesis). University of Toronto. Cite
Hu, J. (2019). Characterization of Pipeline Exterior and Interior Coating Material (MASc Thesis). University of Toronto. Cite
Zhou, H., Abdelaziz, A., & Grasselli, G. (2018). Rock Dilation and Its Effect on Fracture Transmissivity (p. 6). Presented at the SPE/AAPG/SEG Unconventional Resources Technology Conference, URTEC: Unconventional Resources Technology Conference. Cite
Zhou, H., & Grasselli, G. (2018). Dilation of rock joints based on quantified surface description. Presented at the 52nd U.S. Rock Mechanics/Geomechanics Symposium, Seattle: American Rock Mechanics Association (ARMA). Cite
Zhou, H., Zhao, Q., & Grasselli, G. (2018). Dilation of rock joints based on quantified surface description. Presented at the Geoconvention 2018, Calgary. Cite
Zhao, Q., & Grasselli, G. (2018). Understanding shear behaviour of a rough joint using surface topography scan and numerical simulation. Presented at the Geoconvention 2018, Calgary. Cite
Tatone, B. S. A., & Grasselli, G. (2015). A combined experimental (micro-CT) and numerical (FDEM) methodology to study rock joint asperities subjected to direct shear. 49th U.S. Rock Mechanics / Geomechanics Symposium 2015 (Vol. 1, pp. 38–47). Presented at the 49th U.S. Rock Mechanics/Geomechanics Symposium, San Francisco, California: American Rock Mechanics Association (ARMA).Scopus. Cite
Tatone, B. S. A., & Grasselli, G. (2013). An Investigation of Discontinuity Roughness Scale Dependency Using High-Resolution Surface Measurements. Rock Mechanics and Rock Engineering, 46(4), 657–681. Cite
Tatone, B. S. A., & Grasselli, G. (2012). Quantitative Measurements of Fracture Aperture and Directional Roughness from Rock Cores. Rock Mechanics and Rock Engineering, 45(4), 619–629. Cite
Cottrell, B., Tatone, B. S. A., & Grasselli, G. (2010). Joint replica shear testing and roughness degradation measurement. Rock Mechanics in Civil and Environmental Engineering - Proceedings of the European Rock Mechanics Symposium, EUROCK 2010 (pp. 207–210). Presented at the ISRM International Symposium-EUROCK 2010, Lausanne, Switzerland.Scopus. Cite
Tatone, B. S. A., & Grasselli, G. (2009). Use of a Stereo-Topometric Measurement System for the Characterization Of Rock Joint Roughness In-Situ and in the Laboratory. Presented at the RockEng09, Toronto, Canada. Cite
Nasseri, M. H. B., Tatone, B. S. A., Grasselli, G., & Young, R. P. (2009). Fracture Toughness and Fracture Roughness Interrelationship in Thermally treated Westerly Granite. In S. Vinciguerra & Y. Bernabé (Eds.), Rock Physics and Natural Hazards (pp. 801–822). Basel: Birkhäuser Basel. Cite
Nasseri, M., Grasselli, G., Mohanty, B., & Cho, S. (2007). Three-dimensional observation of the fracture process zone in anisotropic granitic rock by x-ray CT scan. Presented at the 7th Euro-Conference of Rock Physics and Geomechanics, Erice, Italy. Cite
Grasselli, G., Wirth, J., & Egger, P. (2002). Quantitative three-dimensional description of a rough surface and parameter evolution with shearing. International Journal of Rock Mechanics and Mining Sciences, 39(6), 789–800. Cite
Grasselli, G., Egger, P., Wirth, J., & Hopkins, D. (2001). Characterization of the parameters that govern the peak shear strength of rock joints. In Elsworth, Tinucci, & Heasley (Eds.), DC Rocks 2001 - 38th U.S. Symposium on Rock Mechanics (USRMS) (pp. 817–821). Presented at the 38th U.S. Symposium on Rock Mechanics, DC Rocks 2001, American Rock Mechanics Association (ARMA).Scopus. Cite
Grasselli, G. (2001). Shear strength of rock joints based on quantified surface description (PhD Thesis). EPFL (Lausanne). Cite
Grasselli, G., & Egger, P. (2000). Shear strength equation for rock joints, based on 3D surface characterization. ISRM International Symposium 2000, IS 2000. Presented at the ISRM International Symposium 2000, IS 2000, Melbourne, Australia: International Society for Rock Mechanics.Scopus. Cite
Grasselli, G., & Egger, P. (2000). 3D surface characterization for the prediction of the shear strength of rough joints (pp. 281–286). Presented at the EUROCK 2000 Symposium, VGE. Cite
Grasselli, G., & Egger, P. (2000). Three-dimensional optical measurement and characterization of rough surfaces. Presented at the GSA meeting, Reno, USA. Cite

Material Fabrication: ExOne Innovent Particulate Printer

The ExOne particulate printer uses an additive manufacturing process that selectively bind thing layers of particulate, ranging from metals to sand, to make a near-net shape object. Rock analogues can be printed and cured in short amounts of time, mimicking real pore structures and pathways, allowing realistic reproductions of rock samples. Being able to produce medium-strength sandstones in prescribed shapes and geometries, the ExOne Innovent particulate printer aids in investigating the role of internal fractures and defects in rock mechanical testing.

Precision Delivery Syringe pumps: Vindum VP-Series

The VP-series pumps available at our labs are able to pump at a large range of high pressures at very precise flow rates. Dual cylinder pumps allow continuous delivery without interruption in flow, and with an external reservoir, is able to provide unlimited volumes of viscosities up to ~200,000cps. A hastalloy housing allows us to delivery highly saline solutions as well, making a large range of possible experimental conditions. The two cylinders can also maintain pressure in a continuous manner, and produce a self-balancing pressure circuit in a pulse-free delivery manner governed by easily tuned PID controls.

Computation: NVIDIA DGX Station

The NVIDIA DGX Station is a powerful computer that packs server-grade hardware into a workstation for high performance computing. The highlight of the system is that it is equipped with 4 state-of-the-art 32 GB Quadro V100 GPUs with NVLink. Addtionally, it is equipped with an Intel Xeon 20-core CPU and 256 GB of system memory. Due to the nature of FDEM, it is an extremely computationally expensive task. With this workstation, we are able to run much larger models due to the higher GPU memory, and finish simulations much faster due to the powerful computational architecture of modern GPUs.

Computation: NVIDIA Titan XP GPUs

Thanks to NVIDIA and their NVIDIA GPU Grant program, the Geomechanics group were donated two Titan XP GPUs (2017 and 2018) as a part of NVIDIA’s Higher Education and Research initiatives. This has been instrumental in increasing the Finite-Discrete Element Method (FDEM) modelling capacity of our research group. The use of GPU accelerated FDEM modelling in Geomechanica’s highly realistic Irazu software requires equally powerful parallel processing power. With incoming projects requiring complex, fully coupled hydro-geomechanical simulations, the Titan XP GPUs vastly increased the simulation speed and complexity of the work in our research group.

Li, M., Magsipoc, E., Abdelaziz, A., Ha, J., Peterson, K., & Grasselli, G. (2021). Mapping Fracture Complexity of Fractured Shale in Laboratory: Three-dimensional Reconstruction From Serial-section Images. Rock Mechanics and Rock Engineering. Cite
Abdelaziz, A., & Grasselli, G. (2021). Modelling Failure in Layered Geological Formations - FDEM: A Micro-mechanical Approach that Bridges Across Scales. In A. Di Donna & D. Sterpi (Eds.), Challenges and Innovations in Geomechanics (pp. 140–155). Presented at the 16th International Conference of IACMAG 2021: Challenges and Innovations in Geomechanics, Springer, Cham. Cite
Ha, J., & Grasselli, G. (2020). Simulating the Excavation Damaged Zone of A Supported Deep Geological Repository Using FDEM (p. 6). Presented at the 54th U.S. Rock Mechanics/Geomechanics Symposium, ARMA: American Rock Mechanics Association. Cite

Tormach 770M CNC Mill

Thanks to a generous donation from PETRONAS Canada, our Geomechanic’s group acquired the Tormach 770M precision mill, equipped with a Vortec 621 cold air gun for water-free milling. Obtaining this CNC mill was a large boon to our research efforts, as conventional coring methods for extracting intact samples for rock mechanics testing can be insufficient. Using a water-free cooling system ensures high sample retrieval rates when milled instead of cored, especially so for highly fractured, water sensitive media such as shales and siltstones. Combined with specialized low-impact methods of sample preparation, difficult testing programs involving limited in-situ/cored samples from large depths become standard procedure in the Geomechanic’s group. In addition, this setup will allow us to mill titanium to plastics alike, to be used for everything from sample preparation to custom design of mechanical components.