EARTHQUAKE AND NUCLEAR PLANT - IMPROVING AND SUSTAINING SAFETY Rota%on wave-field analysis F. Hollender, S. Sbaa, A. Mariscal, V. Perron, A. Imi8az, 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 perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 1 OUTLINE § “6 DOF” analysis (analysis from co-loca;on of “transla;on sensor” and “rotaon sensor”) § Rota;on sensor data vs translaon sensor array spaal derivave § New 2017-2018 experiment SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 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 perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 13 ROTATION SENSOR VS ARRAY SPATIAL DERIVATIVE SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 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 perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 15 TIME HISTORIES SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 16 SPATIAL VARIABILITY SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 17 NEW 2017-2018 EXPERIMENT § Test of Eentec R2 sensor § Small aperture array to beTer compare spaal derivave and rotaon field § 7 months of conAnuous recordings Eentec R2 7 m Broad band velocimeters Rotation sensor 2.5 m SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 18 TEMPORARY SEISMOMETER DENSE ARRAY SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 19 TEMPORARY SEISMOMETER DENSE ARRAY SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 20 TEMPORARY SEISMOMETER DENSE ARRAY SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 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 MeeAng Nov. 9-10, 2017 22 CONCLUSIONS § First study of differences in rotaon wavefield between rock and soil site condiAons § Rotaon measurements are promising for a beTer understanding of whole wave-field composiAon (to avoid deployment of large array): need of instrumental improvements § Ongoing measurements with 1 rotaon sensor in water pump and 1 rotaon sensor in Koutavos § Perspecves: – Finalizaon of analysis of post-seismic rock array (spaal derivave) – Analysis of recent “mini-array” experiment – Analysis of importance of ground moAon rotaon for structure behavior (are ground mo8on rota8ons significant or not compared to the ones induced by dissymmetrical structures?) SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 23 Thank you! SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) SINAPS@ project Cephalonia-ARGONET test-site: outcomes and perspecAves 25-26 Sept. 2018, Cephalonia, Argostoli (Greece) 24 .