Publication Date:
2022-05-04
Description:
The liquefaction phenomenon that occurred in the coseismic phase of th eMay 20,2012 Emilia(Italy)
earthquake (ML5.9) is investigated. It was induced by the water pressure increase in the buried and
confined sand layers.The level-ground liquefactionwastheresultofachaoticgroundoscillationcaused
by theearthquakeshakingandtheobservedfailureswereduetotheupwardwaterflowcausedby
the excessofporepressures.Weexploitedthecapabilityofthedifferentialsyntheticapertureradar
interferometry (DInSAR)techniquetodetectsoilliquefactionsandestimatetheirsurfacedisplacements,
as wellasthehighsensitivitytosurfacechangesofcomplexcoherence,SARbackscatteringandintensity
correlation. Tothisaim,asetoffourCOSMO-SkyMedX-bandSARimages,coveringtheperiodApril
1–June 6,2012,wasused.Geological–geotechnicalanalysiswasalsoperformedinordertoascertainif
the detectedSAR-basedsurfaceeffectscouldbeduetothecompactioninducedbyliquefactionofdeep
sandy layers.Inthisregards,theresultsobtainedfrom13electricalconepenetrometertestsshowthe
presence ofafinetomediumsandylayeratdepths,rangingbetween9and13m,whichprobablyliquefied
during theearthquake,inducingverticaldisplacementsbetween3and16cm.Thequantitativeresults
from geological–geotechnicalanalysisandthesurfacepunctualeffectsmeasuredbyDInSARareingood
agreement, evenifsomedifferencesarepresent,probablyascribabletothelocalthicknessanddepth
variability ofthesandylayer,ortolackofdeformationdetectionduetoDInSARdecorrelation.Theadopted
approach permittedustodefinetheextentoftheareasthatunderwentliquefactionandtoquantifythe
local subsidencerelatedtothesephenomena.Thelatterachievementprovidesusefulinformationthat
must beconsideredinengineeringpractices,intermsofexpectedverticaldeformations.
Description:
Published
Description:
65-78
Description:
6A. Monitoraggio ambientale, sicurezza e territorio
Description:
JCR Journal
Description:
restricted
Keywords:
liquefaction, change detection, intensity correlation DInSAR
;
04. Solid Earth::04.06. Seismology::04.06.04. Ground motion
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
Permalink
