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Correlation Between Fracture Network Properties and Stress Variability in Geological Media
Author(s) -
Lei Qinghua,
Gao Ke
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2018gl077548
Subject(s) - geology , stress (linguistics) , stress field , fracture (geology) , finite element method , geotechnical engineering , physics , philosophy , linguistics , thermodynamics
We quantitatively investigate the stress variability in fractured geological media under tectonic stresses. The fracture systems studied include synthetic fracture networks following power law length scaling and natural fracture patterns based on outcrop mapping. The stress field is derived from a finite‐discrete element model, and its variability is analyzed using a set of mathematical formulations that honor the tensorial nature of stress data. We show that local stress perturbation, quantified by the Euclidean distance of a local stress tensor to the mean stress tensor, has a positive, linear correlation with local fracture intensity, defined as the total fracture length per unit area within a local sampling window. We also evaluate the stress dispersion of the entire stress field using the effective variance, that is, a scalar‐valued measure of the overall stress variability. The results show that a well‐connected fracture system under a critically stressed state exhibits strong local and global stress variabilities.