Martino - microseismicity related

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International Conference Vajont2013 - 8 October

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Martino - microseismicity related

  1. 1. MICROSEISMICITY RELATED TO GRAVITYINDUCED SLOPE DEFORMATIONS FOR RISK MANAGEMENT Lenti L.1, Martino S.2, Paciello A.3, Prestininzi A.2, Rivellino S.2 1 - The French Institute of Science and Technology for Transport, Development and Networks (IFSTTAR) – Paris 2 - Research Centre for Geological Risks (CERI) – University of Rome “Sapienza” - Italy 3 – Agenzia Nazionale per le Nuove Tecnologie l’Energia e lo Sviluppo Sostenibile (ENEA) – Italy
  2. 2. TOPIC . Lenti, L., Martino, S., Paciello, A., Prestininzi, A. & Rivellino, S. (2012). Microseismicity within a karstified rock mass due to cracks and collapses triggered by earthquakes and gravitational deformations. Natural Hazards, 64: 359–379. Maffei, A., Martino, S. & Prestininzi, A. (2005). From the geological to the numerical model in the analysis of the gravity-induced slope deformations: an example from the Central Apennines (Italy). Engineering Geology, 78: 215– 236. Martino, S., Prestininzi, A. & Scarascia Mugnozza, G. (2004). Geologicalevolutionary model of a gravity-induced slope deformation in the carbonate central Apennines (Italy). Q J Eng Geol and Hydr, 37(1): 31–47. CASE STUDY MONITORING ALARM STRATEGY OBJECT Managing the geological risk due to gravitational instabilities in a strategic infrastructure METODOLOGY - Seismometric monitoring - Autodetection - Data processing AIM Fix an “Alert strategy” by means of control indexes derived from the monitoring system for managing the geological risk Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 2
  3. 3. TOPIC CASE STUDY MONITORING ALARM STRATEGY Geographical location: Italian Central Apennines Gran Sasso Vulcano Laziale thrus Fucino th Maiella fault Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 3
  4. 4. TOPIC CASE STUDY ALARM STRATEGY MONITORING Geological setting of the Peschiera Springs slope Slope debris Giurassic limestones Giurassic limestones Malm p.p. “canalone ” fault Giurassic limestones - Malm sup. Scaglia detritica Pendenza fault Red clays Fiamignano-Micciani fault Cretaceous limestone Arenaceous Flysch - Miocene sup. modified from Martino et al., 2004 Cretaceou s limestones Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 4
  5. 5. TOPIC CASE STUDY MONITORING ALARM STRATEGY Gravitational slope deformations of the Peschiera Spring slope: aerieal photo view trenches transversal scarps debris fan Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 5
  6. 6. CASE STUDY TOPIC ALARM STRATEGY MONITORING Evidences on the slope of hypogeous karst processes a a b a a a a 1.80 m a Limestone 2.40 m modified from Maffei et al., 2005 b b Trench debris from Martino et al., 2004 Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 6
  7. 7. CASE STUDY TOPIC MONITORING ALARM STRATEGY Accelerometric network within the slope F1 Sensors: KINEMETRICS EPISENSOR GA Data logger: KINEMETRICS K2 Interconnection: KINEMETRICS cable C6 C1 N Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 7
  8. 8. TOPIC CASE STUDY MONITORING ALARM STRATEGY Seismometric array: location of the recording stations E W Highly jointed and dislodged rock mass Scarps and jointed rock mass bands Microseismicity related to gravityinduced slope deformations for risk management Trench es 31/10/13 Page 8
  9. 9. TOPIC earthquake CASE STUDY MONITORING crack Microseismicity related to gravityinduced slope deformations for risk management ALARM STRATEGY collapse 31/10/13 Page 9
  10. 10. TOPIC CASE STUDY MONITORING ALARM STRATEGY Location of the hypogeous events: pattern of attenuation (microearthquake event) E W Highly jointed and dislodged rock mass Scarps and jointed rock mass bands Microseismicity related to gravityinduced slope deformations for risk management Trenches 31/10/13 Page 10
  11. 11. TOPIC CASE STUDY MONITORING ALARM STRATEGY Location of the hypogeous events: pattern of attenuation (collapse event) E W Highly jointed and dislodged rock mass Scarps and jointed rock mass bands Microseismicity related to gravityinduced slope deformations for risk management Trenches 31/10/13 Page 11
  12. 12. TOPIC CASE STUDY MONITORING ALARM STRATEGY Autodetection of the recorded events modified from Lenti et al., 2012 VI = PGA variation index (%) Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 12
  13. 13. TOPIC CASE STUDY MONITORING ALARM STRATEGY 1471 seismic events 990 earthquakes 391 microearthquakes 91 collapses . 1) 2009 L’Aquila seismic sequence, 2) the 2009 Valle dell’Aterno Gran Sasso – Monti della Laga sequence; 3) the 2009 Reatini mountains sequence; 4) a micro-earthquake sequence; 5) the April 2010 micro-earthquake sequence due to collapses; 6) the 2010 Reatini mountains sequence; 7) the 11 March 2011 Japan teleseismic event; 8) a rock-fall event of approximately 100 m3 occurred on 2011 from a scarp located on the slope surface; 9) the June 2011 micro-earthquake sequence; 10) the September 2011 micro-earthquake sequence due to 15 collapses occurred within approximately half an hour; 11) the Emilia seismic sequence; 12) the September 2012 micro-earthquake sequence due to underground collapses. Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 13
  14. 14. TOPIC CASE STUDY ALARM STRATEGY MONITORING . 1) 2009 L’Aquila seismic sequence, 2) the 2009 Valle dell’Aterno - Gran Sasso – Monti della Laga sequence; 3) the 2009 Reatini mountains sequence 11 March Honshu displacement 1 mm monitored joints Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 14
  15. 15. TOPIC CASE STUDY ALARM STRATEGY MONITORING 7) the 11 March 2011 Japan teleseismic event 11 March Honshu displacement 1 mm monitored joints Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 15
  16. 16. TOPIC CASE STUDY MONITORING ALARM SYSTEM Teleseismic events: the 11 March 2011 Japan earthquake max acc = 300 cm/s2 max vel = 30 cm/s max disp = 150 cm cum Arias = 1E-1 g2s main frequency = 1.5 Hz main period = 3 s max acc = 0.03 cm/s2 max vel = 0.06 cm/s max disp = 0.5 cm cumArias = 1E-8 g2s main frequency = 0.05 Hz main period = 20 s Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 16
  17. 17. TOPIC CASE STUDY ALARM STRATEGY MONITORING . 12) the September 2012 micro-earthquake sequence due to underground collapses 11 March Honshu displacement 1 mm monitored joints Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 17
  18. 18. TOPIC CASE STUDY ALARM STRATEGY MONITORING 5 June 2011 and 23 September 2011 collapses 13 September 2012 collapse 23/09/2011 Observed damage area Record station C1 C6 Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 18
  19. 19. TOPIC CASE STUDY MONITORING ALARM STRATEGY Prevision based on the “rate of effect occurrence” alarm state alert state awareness state from Szwedzicki, 2003 Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 19
  20. 20. CASE ALARM MONITORING STUDY STRATEGY Prevision based on the “rate of effect occurrence” as well as on the “frequency of occurrence” TOPIC microearthquakes from Lenti et al., 2012 Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 20
  21. 21. TOPIC CASE STUDY MONITORING ALARM STRATEGY “Alarm strategy” based on the Control Index (CI(P,t)) CI(P,t) derived from FI(P,t)+EI(P,t) Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 21
  22. 22. TOPIC CASE STUDY MONITORING ALARM STRATEGY Monitoring system: plant zones and accelerometric stations nord plant F1 lant central p west plant est plant GA C1 C6 Alert – west plant: 23/09/2012 Microseismicity related to gravityinduced slope deformations for risk management 31/10/13 Page 22
  23. 23. CONCLUSIONS – 1 . Lenti, L., Martino, S., Paciello, A., Prestininzi, A. & Rivellino, S. (2012). Microseismicity within a karstified rock mass due to cracks and collapses triggered by earthquakes and gravitational deformations. Natural Hazards, 64: 359–379. Maffei, A., Martino, S. & Prestininzi, A. (2005). From the geological to the numerical model in the analysis of the gravity-induced slope deformations: an example from the Central Apennines (Italy). Engineering Geology, 78: 215– 236. Martino, S., Prestininzi, A. & Scarascia Mugnozza, G. (2004). Geologicalevolutionary model of a gravity-induced slope deformation in the carbonate central Apennines (Italy). Q J Eng Geol and Hydr, 37(1): 31–47. 1) The rock mass spreading of the Peschiera Springs slope (Central Italy) is responsible for underground failures (including collapses) which involve the drainage system of the Rome’s aqueduct 2) An integrated monitoring system was devoted so far to recognise different types of seismic events (i.e earthquakes, collapses and cracks) as well as to record induced displacements along rock mass joints Microseismicity due to gravityrelated to gravityinduced rock-mass deformations slope deformations for risk related alarm and management system 31/10/13 Page 23
  24. 24. CONCLUSIONS – 2 . Lenti, L., Martino, S., Paciello, A., Prestininzi, A. & Rivellino, S. (2012). Microseismicity within a karstified rock mass due to cracks and collapses triggered by earthquakes and gravitational deformations. Natural Hazards, 64: 359–379. Maffei, A., Martino, S. & Prestininzi, A. (2005). From the geological to the numerical model in the analysis of the gravity-induced slope deformations: an example from the Central Apennines (Italy). Engineering Geology, 78: 215– 236. Martino, S., Prestininzi, A. & Scarascia Mugnozza, G. (2004). Geologicalevolutionary model of a gravity-induced slope deformation in the carbonate central Apennines (Italy). Q J Eng Geol and Hydr, 37(1): 31–47. 3) An “alarm strategy” was developed attributing three levels of alarm (ordinary, alert and emergency) to four different sectors of the plant, i.e represented by each installed accelerometric station station. 4) The different levels of alarm correspond to specific procedures that are adopted for managing the geological risk in the plant Microseismicity due to gravityrelated to gravityinduced rock-mass deformations slope deformations for risk related alarm and management system 31/10/13 Page 24
  25. 25. FUTURE PERSPECTIVES . Lenti, L., Martino, S., Paciello, A., Prestininzi, A. & Rivellino, S. (2012). Microseismicity within a karstified rock mass due to cracks and collapses triggered by earthquakes and gravitational deformations. Natural Hazards, 64: 359–379. Maffei, A., Martino, S. & Prestininzi, A. (2005). From the geological to the numerical model in the analysis of the gravity-induced slope deformations: an example from the Central Apennines (Italy). Engineering Geology, 78: 215– 236. - A nanoseismometric network has been recently installed within the slope to detect and locate precursors of collapses. - New accelerometric stations are going to be installed on the slope for providing a more reliable location of the recorded microeathquakes. Martino, S., Prestininzi, A. & Scarascia Mugnozza, G. (2004). Geologicalevolutionary model of a gravity-induced slope deformation in the carbonate central Apennines (Italy). Q J Eng Geol and Hydr, 37(1): 31–47. Microseismicity due to gravityrelated to gravityinduced rock-mass deformations slope deformations for risk related alarm and management system 31/10/13 Page 25
  26. 26. Thanks for your attention salvatore.martino@uniroma1.it Geo-slopestabSPZ@ GeoslopestabSPZ Geo-slopestability "Sapienza" I Rischi Naturali in Italia… e a Roma? Salvatore Martino 31/10/13 Page 26

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