Comparison of DFN Modelled Microfracture Systems with Petrophysical Data in Excavation Damaged Zone
| Autor: | Kiuru, Risto, Király, Dorka, Dabi, Gergely, Jacobsson, Lars |
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| Přispěvatelé: | Department of Civil Engineering, Budapest University of Technology and Economics, University of Szeged, RISE Research Institutes of Sweden, Aalto-yliopisto, Aalto University |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Excavation damage
Percolation cluster lcsh:T discrete fracture network model Physical properties of rocks simulation petrophysics physical properties of rocks lcsh:Technology lcsh:QC1-999 Discrete fracture network model percolation cluster Laboratory testing Petrophysics lcsh:Chemistry lcsh:Biology (General) lcsh:QD1-999 laboratory testing lcsh:TA1-2040 excavation damage lcsh:Engineering (General). Civil engineering (General) lcsh:QH301-705.5 Simulation lcsh:Physics |
| Zdroj: | Applied Sciences, Vol 11, Iss 2899, p 2899 (2021) Applied Sciences Volume 11 Issue 7 |
| ISSN: | 2076-3417 |
| Popis: | Funding Information: This research is based on work funded by Posiva Oy. This research was funded by the Academy of Finland, grant number 319798. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Copyright: Copyright 2021 Elsevier B.V., All rights reserved. Physical and petrographic properties of drill core specimens were determined as a part of investigations into excavation damage in the dedicated study area in the ONKALO® research facility in Olkiluoto, Western Finland. Microfractures in 16 specimens from two drillholes were analysed and used as a basis for fractal geometry-based discrete fracture network (DFN) modelling. It was concluded that the difference in resistivity between pegmatoid granite (PGR) and veined gneiss (VGN) specimens of similar porosity was likely due to differences in the types of microfractures. This hypothesis was confirmed from microfracture analysis and simulation: fractures in gneiss were short and mostly in one preferred orientation, whereas the fractures in granite were longer and had two preferred orientations. This may be due to microstructure differences of the rock types or could suggests that gneiss and granite may suffer different types of excavation damage. No dependencies on depth from the excavated surface were observed in the geometric parameters of the microfractures. This suggests that the excavation damaged zone cannot be identified based on the changes in the parameters of the microfracture networks, and that the disturbed layer observed by geophysical methods may be caused by macro-scale fractures. |
| Databáze: | OpenAIRE |
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