Rotation Wave-Field Analysis. (F. Hollender)
EARTHQUAKE AND NUCLEAR PLANT - IMPROVING AND SUSTAINING SAFETY
Rota on wave-field analysis F. Hollender, S. Sbaa, A. Mariscal, V. Perron, A. Imi az, P.-Y. Bard, A. Cochard
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspectives 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 1 OUTLINE
§ “6 DOF” analysis (analysis from co-loca on of “transla on sensor” and “rota on sensor”)
§ Rota on sensor data vs transla on sensor array spa al deriva ve
§ New 2017-2018 experiment
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 2 FEW HISTORICAL EXAMPLES
Rotation of the San Bruno obelisk Rotation of the monument to George Inglis (India) after the 1783 Calabria earthquake after the 1897 Great Shillong earthquake
Ground motion rotation or rotation induced by ground motion rotation translation in dissymmetrical structures ?
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 3 REAL GROUND MOTION: 6 DEGREES OF FREEDOM
Rocking
Torsion
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 4 MEASUREMENT LOCATIONS
Location of the study site.
a Kefalonia Island with respect to Greece.
b The Argostoli area with respect to Kefalonia Island.
c Geological map of the Argostoli–Koutavos area
Eentec R1
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 5 THE 3 POST-SEISMIC SURVEY 6-DOF DATASETS
Map of the locations of the events for the Kefalonia Island datasets.
a Recording phase 1: soft-soil site, at the center of the former NERA project dense array.
b Recording phase 2: rock site, at the center of the SINAPS@ project dense array.
c Recording phase 3: soft-soil site, at the Argonet array.
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 6 THE 3 POST-SEISMIC SURVEY 6-DOF DATASETS
Main characteristics of the datasets used in the present study (PGTA: peak ground translational acceleration)
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 7 « 6-DOF » WAVEFIELD ANALYSIS
Example time histories.
(a) Records from the
rock site (ML=3.9; Rhypo=15.9 km).
(b) Records from the
soft-soil site (ML=5.0; Rhypo=20.2 km).
Left: Rotation sensor records.
Right: Translational sensor records.
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 8 Examples of the signal and noise spectra (Fourier amplitude spectrum density, ASD) and the corresponding signal-to-noise ratio. a Records from the rock site (phase 2). b Records from the soft-soil site (phase 3).
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 9 PG(T)A/PGR(V) CORRELATIONS
Peak ground translation acceleration (PGTA) versus peak ground rotation velocity (PGRV) correlations for the two sites of the present study and from the three datasets from the literature. (a) All events. (b) Regression lines.
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 10 EFFECT OF SITE CONDITIONS ON ROTATIONS
Correlation between rotation velocity and peak ground translational
acceleration (PGTA), with a differentiation between torsion/ PGTAH (a, top) and rocking/ PGTAZ (b, bottom) for the two sites of the present study and for the Yin et al. (2016) GVDA site. Left: All events. Right: Regression lines.
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 11 Comparison of Love-wave phase velocity estimated using rotation sensor data and inferred from shear-wave velocity profiles (based on geophysical measurements) on both Kefalonia soft-soil and rock sites
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 12 ANALYSIS OF LOVE/RAYLEIGH RATIOS
Analysis of the ratios between the L/R energies using dense array analysis data and rotation sensor data for the two Kefalonia sites. (a) Proportion of surface-wave energy with respect to total ground motion energy from dense array analysis. (b) HVSR from ambient vibration recordings. (c) Love to Rayleigh energy ratios.
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 13 ROTATION SENSOR VS ARRAY SPATIAL DERIVATIVE
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 14 COMPARISON IN FOURIER DOMAIN
Spectral comparison of the array-derived rotation rate and the one recorded from the rotation sensor for the 10 m radius for the event with magnitude 5, epicentral distance 9 km that occurred on the 22nd of February, 2014. The black line represents �↓���
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 15 TIME HISTORIES
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 16 SPATIAL VARIABILITY
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 17 NEW 2017-2018 EXPERIMENT
§ Test of Eentec R2 sensor § Small aperture array to be er compare spa al deriva ve and rota on field § 7 months of con nuous recordings
Eentec R2
7 m Broad band velocimeters
Rotation sensor 2.5 m
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 18 TEMPORARY SEISMOMETER DENSE ARRAY
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 19 TEMPORARY SEISMOMETER DENSE ARRAY
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 20 TEMPORARY SEISMOMETER DENSE ARRAY
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 21 QUICK COMPARISON BETWEEN SEISMOLOGIST WORK AND GEOLOGIST WORK…
During the installation of the array in Koutavos...
Fault observation???
SINAPS@ ANR-11-RSNR-0022 Project – Plenary Mee ng Nov. 9-10, 2017 22 CONCLUSIONS
§ First study of differences in rota on wavefield between rock and soil site condi ons § Rota on measurements are promising for a be er understanding of whole wave-field composi on (to avoid deployment of large array): need of instrumental improvements § Ongoing measurements with 1 rota on sensor in water pump and 1 rota on sensor in Koutavos § Perspec ves: – Finaliza on of analysis of post-seismic rock array (spa al deriva ve) – Analysis of recent “mini-array” experiment – Analysis of importance of ground mo on rota on for structure behavior (are ground mo on rota ons significant or not compared to the ones induced by dissymmetrical structures?)
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 23 Thank you!
SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspec ves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 24