Characterization of hydro-mechanical properties of rock fractures using steady state flow tests

Lauri Uotinen, Masoud Torkan, Mateusz Janiszewski, Alireza Baghbanan, Ville Nieminen, Mikael Rinne

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Abstract

Characterization of Hydro-Mechanical (H-M) properties of rock fractures is the initial and important step in modeling of fully H-M coupled processes in fractured rock masses. Fluid flow in the fractured rock mass is an important aspect when evaluating the safety of geological disposal of high-level nuclear waste. Many attempts have been taken to measure and model fluid flow in rock fractures in different stress field conditions. However, still study about the scale effect of fracture properties and confinement stress on the conductivity of rough rock fractures remains a challenging topic of research. As a part of an ongoing research project about fluid flow modeling in fractured rock mass (RAKKA), and as an initial step one rock slab pair with sizes of 250 mm x 250 mm of Kuru grey granite halves was prepared. It has a horizontal mechanically induced tensile fracture. The surface roughness of the fracture was mapped using a conventional profilometer and structure-from-motion photogrammetry before each fluid flow test. The fractures were subjected to different normal stress and then fluid flow within the fractures was conducted linearly from edge to opposite edge with perpendicular edges sealed, and conductivity of the fractures under steady-state condition was measured. Then the test is repeated with all three sides open. The results show anisotropic behaviour in permeability. The diagonal components of the permeability matrix are significantly stress-dependent. Together the new fracture digitization method and the new three-way fluid flow test allow the contactless characterization of hydro-mechanical properties of rock fractures and the validation of the results.
Original languageEnglish
Title of host publicationProceedings of ISRM International Symposium Eurock 2020 - Hard Rock Engineering, Trondheim, Norway, 14-19 June
Publication statusAccepted/In press - 21 Feb 2020
MoE publication typeA4 Article in a conference publication
EventISRM International Symposium - Clarion Hotel & Congress, Trondheim, Norway
Duration: 14 Jun 202019 Jun 2020
http://www.eurock2020.com/

Conference

ConferenceISRM International Symposium
Abbreviated titleEUROCK
CountryNorway
CityTrondheim
Period14/06/202019/06/2020
Internet address

Keywords

  • Rock fracture
  • fluid flow
  • stress-flow coupling
  • scale effect
  • stress effect

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  • Projects

    RAKKA: Rakoilleen kalliomassan vedenjohtavuus

    Rinne, M., Uotinen, L. & Torkan, M.

    01/02/201931/12/2020

    Project: Other external funding: Other government funding

    Cite this

    Uotinen, L., Torkan, M., Janiszewski, M., Baghbanan, A., Nieminen, V., & Rinne, M. (Accepted/In press). Characterization of hydro-mechanical properties of rock fractures using steady state flow tests. In Proceedings of ISRM International Symposium Eurock 2020 - Hard Rock Engineering, Trondheim, Norway, 14-19 June