Scale and stress effects on permeability tensor of fractured rocks with correlated fracture length and aperture
2008 (English)In: Thermo-Hydromechanical and chemical coupling in geomaterials and applications: Proceedings of the 3rd International Symposium GeoProc’2008 / [ed] Nicolas Burlion, Jian-Fu Shao, 2008, 439-446 p.Conference paper (Refereed)
The effect of stress on permeability tensor and Representative Elementary Voliume (REV) of fractured rock masses is studied using a Discrete Element Approach (DEM). A new nonlinear model of rock fractures is developed for prediction of normal stress-normal displacement behavior of fractures based on the correlation between fracture aperture and length distributions. The results show that at small differential stress ratios K (=horizontal/vertical stresses) the overall permeability of fracture networks is generally decreased. However contribution from a few large fractures of higher hydraulic conductivity prevents drastic reduction of the overall permeability, compare with DFN models of constant fracture apertures regardless of fracture trace length. With large values of differential stress ratios, the overall permeability of the DFN models is controlled by a combination of highly conductive larger fractures and fractures with shear slipping and dilation. With increasing differential stress ratios (K=1,3,4 and 5) the REV of a fractured rock may exist at much larger model sizes comparing with the model without stress (K=0).
Place, publisher, year, edition, pages
2008. 439-446 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:kth:diva-8523ISBN: 978-1-84821-043-1OAI: oai:DiVA.org:kth-8523DiVA: diva2:13870
3rd International Symposium GeoProc’2008, Lille, France
QC 20100702. Uppdaterad från manuskript till konferensbidrag (20100702).2008-05-272008-05-272010-07-06Bibliographically approved