Weitere Kapitel dieses Buchs durch Wischen aufrufen
This chapter illustrates the concept of passive seismics as a method for monitoring the propagation of cracks within a rock mass as a result of load stress or water freezing in view of the use of this technique for rockfall early warning. The methodology is still far from being a standard and consolidated technique. The research is making progress, but just a few real case studies are documented. They are shortly overviewed in the introduction. Then, an interesting field test where crack propagation was artificially triggered up to full rock detachment, while a small sensor network was active, is discussed to show the existence and the characteristics of precursory signals. It follows the illustration of the microseismic monitoring methodology through the description of the Mt. San Martino (Lecco, Italy) sensor network and the discussion of the preliminary results obtained during the initial months of activity. Apparently, the preliminary results show some correlation with rainfalls, but not with temperature. Microseismic spectra are mainly concentrated in the first 100 Hz. This probably means that the hypocentre distances from the sensors are quite longer than 10 m. Electromagnetic interferences are also observed as mentioned by other authors who have analyzed data sets from other microseismic networks installed in mountain regions. They are automatically discriminated from significant signals by a classification software which works on the time/frequency properties of these events. Hypocenter localization and clustering analysis of the significant events are the planned near-future activities.
Bitte loggen Sie sich ein, um Zugang zu diesem Inhalt zu erhalten
Sie möchten Zugang zu diesem Inhalt erhalten? Dann informieren Sie sich jetzt über unsere Produkte:
Amitrano, D., Arattano, M., Chiarle, M., Mortara, G., Occhiena, C., Pirulli, M., & Scavia, C. (2010). Microseismic activity analysis for the study of the rupture mechanism in unstable rock masses. Natural Hazards and Earth System Science,10, 831–841. CrossRef
Arosio, D., Longoni, L., Papini, M., Scaioni, M., Zanzi, L., & Alba, M. (2009a). Towards rockfall forecasting through observing deformations and listening to microseismic emissions. Natural Hazards and Earth System Science,9, 1119–1131. CrossRef
Arosio, D., Bernasconi, G., Mazzucchelli, P., Rovetta, D., & Zanzi L. (2009b). Localization algorithms for search and rescue applications. In Exp. Abs. Near Surface 2009, Dublin, Ireland, September 7–9, 2009.
Arosio, D. (2010). A microseismic approach to locate survivors trapped under rubble. Near Surface Geophysics,8, 623–633. CrossRef
Arosio, D., Longoni, L., Mazza, F., Papini, M., & Zanzi, L. (2013). Freeze-thaw cycle and rockfall monitoring. In C. Margottini, et al. (Eds.), Landslide science and practice (Vol. 2, pp. 385–390). Berlin Heidelberg: Springer. CrossRef
Arosio, D., Longoni, L., Tarabini, M., Papini, M., Zanzi, L., & Colombo, M. (2014). Microseismic monitoring of rockfalls: Preliminary interpretation of lab and field tests. In Proceedings of 5th Interdisciplinary Workshop on Rockfall Protection (RocExs 2014). Lecco, Italy, May 29–31, 2014.
Blikra, L. H. (2008). The Åknes rockslide: Monitoring, threshold values and early warning. In Proceedings of 10th International Symposium on Landslides and Engineered Slopes (pp. 1089–1094). Xi’an, P.R. China, June 30–July 4, 2008.
Blikra, L. H. (2012). The Åknes rockslide, Norway. In J. J. Clague & D. Sead (Eds.), Landslides: Types mechanisms and modeling (pp. 323–335). UK: Cambridge University Press. CrossRef
Drew, J., Leslie, D., Armstrong, P., & Michaud, G. (2005). In Proceedings of SPE Annual Technical Conference and Exhibition (paper no. SPE95513). Dallas, TX, USA, October 9–12, 2005.
Hardy, H. R. (2003). Acoustic emission/microseismic activity—Principles, techniques and geotechnical applications. Lisse, The Netherlands: A.A. Balkema Publishers. CrossRef
Helmstetter, A., & Garambois, S. (2010). Seismic monitoring of Séchilienne Rockslide (French Alps): Analysis of seismic signals and their correlation with rainfalls. Journal of Geophysical Research115, Paper no. F03016.
Herath, S. C. K., & Pathirana, P. N. (2013). Robust localization with minimum number of TDOA measurements. IEEE Signal Processing Letters,20(10), 949–951. CrossRef
Senfaute, G., Duperret, A., & Lawrence, J. A. (2009). Micro-seismic precursory cracks prior to rock-fall on coastal chalk cliffs: A case study at Mesnil-Val, Normandie, NW France. Natural Hazards and Earth System Science,9, 1625–1641. CrossRef
Spillmann, T., Maurer, H., Green, A. G., Heincke, B., Willenberg, H., & Husen, S. (2007). Microseismic investigation of an unstable mountain slope in the Swiss Alps. Journal of Geophysical Research112, Paper no. B07301.
Walter, M., Schwaderer, U., & Joswig, M. (2012). Seismic monitoring of precursory fracture signals from a destructive rockfall in the Vorarlberg Alps, Austria. Natural Hazards and Earth System Science,12, 3545–3555. CrossRef
- Analysis of Microseismic Activity Within Unstable Rock Slopes
- Springer Berlin Heidelberg
Fallstudie Überschwemmungskarten/© Thaut Images | Fotolia