Function and Responsibilities:

Postdoc Researcher in the Helmholtz Young Investigator Group "Advanced reservoir engineering concepts for a controlled utilization of deep geothermal energy in urban areas" (ARES)

Research Interests:

• Geoenergy
• Geomechanics
• Faulting mechanics
• Underground engineering 
• Human-induced seismicity
• Experimental rock mechanics/physics

Career:

• 2020-present: Postdoc Researcher, GFZ German Research Centre for Geosciences, Germany
• 04/2019-12/2019: Visiting Researcher, Korea Institute of Civil Engineering and Building Technology, Korea
• 2016-2020: Teaching Assistant and Research Assistant, Nanyang Technological University, Singapore

Education:

• 2020: PhD in Civil Engineering (Best PhD Thesis), Nanyang Technological University, Singapore
• 2014: BEng in Mining Engineering (First Class Honours), China University of Mining Technology, China
• 2013: Exchange study in Mining Engineering (Outstanding Exchange Student), University of Wollongong, Australia

Projects:

Open research fund of the State Key Laboratory of Coal Resources and Safe Mining, China: Friction evolution of low-permeability rock fractures during cyclic fluid injection, ¥50, 000, PI, 2021-2022

Research Boards and Committees:

• 2023-present: Scientific Handling Editor, Journal of Rock Mechanics and Geotechnical Engineering (Elsevier)

• 2023-present: Scientific Handling Editor, Deep Underground Science & Engineering (Wiley)

• Guest Editor (Topic: Recent Advances in Mechanics and Physics of Rock Fractures across Scales) of Frontiers in Earth Science: https://www.frontiersin.org/research-topics/23769/recent-advances-in-mechanics-and-physics-of-rock-fractures-across-scales

• Guest Editor (Topic: Characterization of the Interactions between Cutting Tools and Rocks during Mechanized Tunneling from a Metallurgical and Rock Mechanical Point of View) of Minerals: https://www.mdpi.com/journal/minerals/special_issues/Cutting_Tools_Rock

• 2021: Session Chair (Topic: Preparation Process of Earthquakes and Related Phenomena) of the 16th Annual Meeting of Asia Oceania Geosciences Society, Singapore

• 2019: Session Convener (Topic: Rock Mechanics for Geothermal Energy) of the 13th Asian Regional Conference of International Association for Engineering Geology and the Environment (IAEG), Singapore

• Proposal Reviews: National Science Center (Poland); National Institute for Ocean Science (Ifremer, France)

• Journal Reviews: Nature Communications; JGR-Solid Earth; International Journal of Rock Mechanics and Mining Sciences; Geophysics; Geothermics; Tectonophysics; Acta Geotechnica; Rock Mechanics and Rock Engineering; Geophysical Journal International; Transport in Porous Media; Engineering Fracture Mechanics; International Journal for Numerical and Analytical Methods in Geomechanics; Journal of Petroleum Science and Engineering; Journal of Rock Mechanics and Geotechnical Engineering; Geomechanics and Geophysics for Geo-Energy and Geo-Resources; Rock Mechanics Bulletin; Engineering; Scientific Reports; Engineering Failure Analysis; Advances in Civil Engineering; Energies; Geofluids; Geosciences; Minerals; Geomechanics and Engineering; Measurement; International Journal of Environmental Research and Public Health; Case Studies in Construction Materials; Material Letters; Applied Sciences; Processes ...

Awards:

• Excellent Scientific Editor Award, Journal of Rock Mechanics and Geotechnical Engineering, 2024
  
• Outstanding Early-career Editorial Board Member, Deep Underground Science and Engineering, 2024
• Outstanding Reviewer Award, Journal of Rock Mechanics and Geotechnical Engineering, 2023
• Outstanding Reviewer Award, Journal of Rock Mechanics and Geotechnical Engineering, 2022
• Best PhD Thesis Award, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 2021
• Best Presentation Award, Society for Rock Mechanics & Engineering Geology, Singapore 2020
• Best Teaching Assistant Award, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 2019
• NTU Research Scholarship (2016-2020), Nanyang Technological University, Singapore, 2016
• Excellence Student Scholarship, China University of Mining and Technology, China, 2016
• Outstanding Undergraduate International Exchange Scholarship, China Scholarship Council, China 2013

Invited Talks

• 08/05/2024 Montanuniversität Leoben, Leoben, Austria
• 13/09/2023 Utrecht University, Utrecht, The Netherlands
• 06/07/2023 Institute of Geomechanics, Chinese Academy of Geological Sciences, Beijing, China
• 30/30/2023 University of Alberta, Alberta, Canada
• 22/03/2023 Hebei University of Technology, Tianjin, China
• 16/03/2023 CY Cergy Paris Université, Paris, France.
  
• 07/07/2022 École des Ponts ParisTech, Paris, France.
• 05/08/2021 Institute of Geology and Geophysics, The Chinese Academy of Sciences, Beijing, China.
• 14/06/2021 Free University of Berlin, Berlin, Germany.
• 26/10/2020 Institute of Rock and Soil Mechanics, The Chinese Academy of Sciences, Wuhan, China.
• 29/09/2020 Beijing University of Technology, Beijing, China.
• 13/01/2020 The University of New South Wales, Sydney, Australia.
• 27/12/2019 Southern University of Science and Technology, Shenzhen, China.
• 17/05/2019 MTS China, Beijing, China.
• 09/06/2018 China University of Mining and Technology, Xuzhou, China.

Publications

Journal Papers (* corresponding author)

• Zhang, S., Ji, Y.*, Hofmann, H., Li, S., Rybacki, E., Zimmermann, G., & Zang, A. (2024). A laboratory study on fluid injection into a fault versus adjacent to a fault: Implications for injection-induced seismicity in EGS. Philosophical Transactions of the Royal Society A, (Accepted, Invited paper)
• Zhang, Y., Ji, Y., Zhao, Y., & Wang, C. (2024). Mechanical anisotropy associated with bedding in shale under Brazilian test conditions: Insights from acoustic emission statistics. Journal of Rock Mechanics and Geotechnical Engineering. https://doi.org/10.1016/j.jrmge.2024.01.006
• Miao, S., Pan, P.*, Zang, A., Zhuang, C., Hofmann, H., Ji, Y.* (2024). Laboratory shear behaviour of tensile- and shear-induced fractures in sandstone: Insights from acoustic emission. Rock Mechanics and Rock Engineering. https://doi.org/10.1007/s00603-024-03780-2
• Ji, Y., Zhang, W., Hofmann, H., Cappa, F., & Zhang, S. (2023). Fracture permeability enhancement during fluid injection modulated by pressurization rate and surface asperities. Geophysical Research Letters, 50(18), e2023GL104662.
  
• Ji, Y., Zhang, W., Hofmann, H., Chen, Y., Kluge, C., Zang, A., & Zimmerman, G. (2023). Modeling of fluid pressure migration in a pressure sensitive fault zone subject to cyclic injection and implications for injection-induced seismicity. Geophysical Journal International, 232(3): 1655-1667.
• Ji, Y., Chen, Y., Hofmann, H., Zhang, Y., Zang, A., & Zimmerman, G. (2023). The role of temperature-enhanced fault closure in promoting post-injection pressure diffusion and seismicity in Enhanced Geothermal Systems. Deep Underground Science and Engineering, 1-12. (Invited paper)
• Hutka., G. A., Cacace, M., Hofmann, H., Zang, A., Wang, L., & Ji., Y. (2023). Numerical investigation of the effect of fluid pressurization rate on frictional strength in injection-induced fault slip experiments. Scientific Reports, 13, 4437.
• Ji, Y., Wang, L., Hofmann, H., Kwiatek, G., & Dresen., G. (2022). High-rate fluid injection reduces the nucleation length of laboratory earthquakes on critically stressed faults in granite. Geophysical Research Letters, 49(23), e2022GL100418.
  
• Ji, Y., Hofmann, H., Rutter, H. E., & Zang, A. (2022). Transition from slow to fast injection-induced slip of an experimental fault in granite promoted by elevated temperature. Geophysical Research Letters, 49(23), e2022GL101212.
• Ji, Y., Hofmann, H., Duan, K., & Zang, A. (2022). Laboratory experiments on fault behavior towards better understanding of injection-induced seismicity in geoenergy systems. Earth-Science Reviews, 103916.
  
• Ji, Y., Hofmann, H., Rutter, H. E., Xiao, F., & Yang, L. (2022). Revisiting the evaluation of hydraulic transmissivity of elliptical rock fractures in triaxial shear-flow experiments. Rock Mechanics and Rock Engineering, 55, 3781-3789. 
• Ji, Y., Kluge, C., Hofmann, H., & Blöcher, G. (2022). Effects of external temperature and fluid volume on laboratory measurements of pore pressure and injected volume in a rock fracture. Journal of Rock Mechanics and Geotechnical Engineering, 14(5), 1461-1469.
• Li, Y.*, Du, X., & Ji, Y.* (2022). Prediction of the transitional normal stress of rock joints under shear. International Journal of Rock Mechanics and Mining Sciences, 159, 105203.
• Ji, Y., Yoon, J. S., Zang, A., & Wu, W. (2021). Mitigation of injection-induced seismicity on undrained faults in granite using cyclic fluid injection: a laboratory study. International Journal of Rock Mechanics and Mining Sciences, 146, 104881.
• Ji, Y., Fang, Z., & Wu, W. (2021). Fluid overpressurization of rock fractures: experimental investigation and analytical modelling. Rock Mechanics and Rock Engineering, 54, 3039-3050.
  
• Ji, Y., Zhuang, L., Wu, W., Hofmann, H., Zang, A., & Zimmermann, G. (2021). Cyclic water injection potentially mitigates seismic risks by promoting slow and stable slip of a natural fracture in granite. Rock Mechanics and Rock Engineering, 54, 5389-5405.
• Ji, Y., Wang, L., Zheng, Y., & Wu, W. (2021). Temperature-dependent abrasivity of Bukit Timah granite and implications for drill bit wear in thermo-mechanical drilling. Acta Geotechnica, 16, 885-893.
• Wei, M., Dai, F., Ji, Y., & Wu, W. (2021). Effect of fluid pressure gradient on factor of safety in rock stability analysis. Engineering Geology, 294, 106346.
• Ji, Y., & Wu, W. (2020). Injection-driven fracture instability in granite: mechanism and implications. Tectonophysics, 791, 228572.
• Ji, Y., Wanniarachchi, W. A. M., & Wu, W. (2020). Effect of fluid pressure heterogeneity on injection-induced fracture activation. Computers and Geotechnics, 123, 103589.
• Rathnaweera, T. D., Wu, W., Ji, Y., & Gamage, R. P. (2020). Understanding injection-induced seismicity in enhanced geothermal systems: From the coupled thermo-hydro-mechanical-chemical process to anthropogenic earthquake prediction. Earth-Science Reviews, 103182.
• Zou, J., Jiao, Y., Tang., Z., Ji, Y., Yan., C., & Wang., J. (2020). Effect of mechanical heterogeneity on hydraulic fracture propagation in unconventional gas reservoirs. Computers and Geotechnics, 125, 103652.
• Ji, Y., Wu, W., & Zhao, Z. (2019). Unloading-induced rock fracture activation and maximum seismic moment prediction. Engineering Geology, 262, 105352.
• Duan, K., Ji, Y., Xu, N., Wan, Z., & Wu, W. (2019). Excavation-induced fault instability: Possible causes and implications for seismicity. Tunnelling and Underground Space Technology, 92, 103041.
• Duan, K., Ji, Y., Wu, W., & Kwok, C. Y. (2019). Unloading-induced failure of brittle rock and implications for excavation-induced strain burst. Tunnelling and Underground Space Technology, 84, 495-506.
• Cheng, J., Wan, Z.*, & Ji, Y.* (2018). Shield-roof interaction in longwall panels: Insights from field data and their application to ground control. Advances in Civil Engineering, 2018, 18.
• Ji, Y., Ren, T., Wynne, P., Wan, Z., Ma, Z., & Wang, Z. (2016). A comparative study of dust control practices in Chinese and Australian longwall coal mines. International Journal of Mining Science and Technology, 26(2), 199-208. (2016 top 10 paper of the journal)
• Cheng, J., Wan, Z., Peng, S. S., Liu, S., & Ji, Y. (2015). What can the changes in shield resistance tell us during the period of shearer’s cutting and neighboring shields’ advance? International Journal of Mining Science and Technology, 25(3), 361-367.

Conference Papers and Abstracts

• Ji, Y., Zhang, S., Hofmann, H., Yeo, I. W., Ge, S., Zimmermann, G., & Li., S. (2024). Mitigated post-injection seismicity associated with fluid extraction in Enhanced Geothermal Systems: Evidence from lab- and field-scale experiments. GEoREST Workshop on Induced Seismicity. 11-13 March 2024, Palma, Mallorca, Spain.
• Ji, Y., Zhang, W., Hofmann, H., & Cappa, F. (2023). Fracture permeability enhancement during fluid injection controlled by pressurization rate and slip velocity. 57th U.S. Rock Mechanics/Geomechanics Symposium. 25-28 June 2023, Atlanta, Georgia, USA. 
• Hofmann, H., Zimmermann, G., Zang, A., Ji, Y., Farkas, M., Hutka, G., Cacace, M., Zhuang, L., & Sabah., M. (2022). Advanced injection protocols for a controlled development of Enhanced Geothermal Systems. CouFrac 2022-3rd International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application. 14-16 Nov. 2022, Berkeley, California, USA.
  
• Ji, Y., Hofmann, H., & Rutter, E. (2022). Temperature effect on injection-induced slip of an experimental fault in granite: implications for injection-induced seismicity in EGS. European Geothermal Congress, 17-21 Oct. 2022, Berlin, Germany.
  
• Ji, Y., Wang, L., Hofmann, H., Kwiatek, G., & Dresen., G. (2022). Injection-rate control on deformation and stress of an experimental fault in granite. EGU General Assembly, 23-27 May. 2022, Vienna, Austria.
  
• Ji, Y., Hofmann, H. (2021). Fluid pressure migration in a fault zone during cyclic injection: mechanisms and implications. AGU Fall Meeting. 13-17 Dec. 2021, New Orleans, USA.
  
• Ji, Y., Zhuang, L., Wu, W., Hofmann, H., Zang, A., & Zimmermann, G. (2020). Cyclic water injection mitigates seismic risks by promoting slow and stable fracture slip. CouFrac2020_International Conference on Coupled Processes in Fractured Geological Media: Observation, Modeling, and Application. 11-13 Nov. 2020, Seoul, Korea.
• Ji, Y., & Wu, W. (2019). Mitigating risks of injection-induced seismicity using cyclic fluid injection: new evidence and insights from the laboratory. AGU Fall Meeting. 9-13 Dec. 2019, San Francisco, USA.
• Jia., Y., Ji, Y., & Wu, W. (2019). Fluid pressure heterogeneity in rock fractures and associated frictional slip. ARMA-CUPB Geothermal International Conference. 5 Aug.-8 Aug. 2019, Beijing, China.
• Ji, Y., & Wu, W. (2019). Injection-driven fracture instability and seismic moment release. 16th Asia Oceania Geoscience Society Annual Meeting. 28 Jul.-2 Aug. 2019, Singapore.
• Wu., W., Ji., Y., & Jia., Y. (2018). Fracture heterogeneity, fluid overpressure, and injection-induced seismicity. AGU Fall Meeting. 10-14 Dec. 2018, Washington, D.C., USA
• Ji, Y., & Wu, W. (2018). Overpressured fluid injection and fault slip triggering. International Symposium on Energy Geotechnics. 25-28 Sep. 2018, Lausanne, Switzerland.
• Ji, Y., & Wu, W. (2018). Overpressure-induced frictional slip of rock fractures. 10th Asian Rock Mechanics Symposium. 29 Oct.-03 Nov. 2018, Singapore.
• Ji, Y., Jia., Y., Rathnaweera, T. D., & Wu, W. (2018). Overpressure-induced fracture slip triggering in granite. 2nd International Conference on Geo-mechanics, Geo-energy and Geo-resources. 22-24 Sep. 2018, Chengdu, China.