0508142 - GFÚ 2020 RIV US eng J - Journal Article
Häusler, M. - Michel, C. - Burjánek, Jan - Fäh, D.
Fracture network imaging on rock slope instabilities using resonance mode analysis.
Geophysical Research Letters. Roč. 46, č. 12 (2019), s. 6497-6506. ISSN 0094-8276. E-ISSN 1944-8007
Institutional support: RVO:67985530
Keywords : rock slope instability * ambient seismic vibrations * frequency domain decomposition * resonance frequency * operational mode analysis * fracture mappings
OECD category: Volcanology
Impact factor: 4.497, year: 2019
Method of publishing: Open access
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2019GL083201

We performed modal analysis using frequency domain decomposition of ambient seismic vibration data collected on large rock slope instabilities. This technique enables a robust detection of resonance frequencies and provides the corresponding mode shape vectors. We applied the technique to synthetic and field data sets acquired by seismometer arrays on two rock instabilities in Switzerland. We found that, at the fundamental mode, the entire instability vibrates in-phase with the dominant mode shape vector oriented perpendicular to dominant fracture systems. At higher frequencies, different compartments of the instability resonate antiphase. Therefore, delineating the zero crossings between the phases allows dominant fractures to be efficiently mapped. Approximately 1 hr of ambient vibration data suffices to apply the method successfully. The method also potentially detects hidden fractures that cannot be observed by geological field mapping. In addition, this approach combines classic amplification and polarization analysis into one technique, simplifying data processing efforts.
Permanent Link: http://hdl.handle.net/11104/0299127