GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 3.2 671 reached an average value of ±50% during the process and these variations are preserved in the time-lapse inverted models. A preliminary interpretation of the presented data could be the following: the left part of the model exhibit excess pore pressure (negative variations), which permitted the water to flow upwards while the right part exhibits consolidation phenomena (positive variations). This interpretation could be confirmed by the increase in the average level of the water table in the external well, with a rate of about 0.25 cm/hit, and with the measures of self-potentials done during the experiment. In fact, the measured self-potential before and after the Dynamic stage, is affected by local variations that might be related to the flow of water in the sand (Fig. 3). These preliminary results indicate that ERT could be a suitable technique to the time-lapse monitoring of the setting up of pore water pressures and liquefaction process. References Abu Zeid, N. et al. (2012) ‘Electrical resistivity tomography investigation of coseismic liquefaction and fracturing at San Carlo, Ferrara Province, Italy’, Annals of Geophysics , 55(4), pp. 713–716. doi: 10.4401/ag-6149. Amoroso, S. et al. (2017) ‘The first Italian blast-induced liquefaction test (Mirabello, Emilia-Romagna, Italy): Description of the experiment and preliminary results’, Annals of Geophysics , 60(5). doi: 10.4401/ag-7415. Apostolopoulos, G. et al. (2013) ‘Geophysical Investigation for the Detection of Liquefaction Phenomena in an Archaeological Site, Lechaion, Greece’, (September 2013). doi: 10.3997/2214-4609.20131379. Boulanger, R. W. and Idriss, I. M. (2014) CPT and SPT based liquefaction triggering procedures , Center for Geotechnical Modeling . Available at: https://faculty.engineering.ucdavis.edu/boulanger/wp-content/uploads/ sites/71/2014/09/Boulanger_Idriss_CPT_and_SPT_Liq_triggering_CGM-14-01_20141.pdf (Accessed: 20 March 2018). de Franco, R. et al. (2018) ‘Geophysical characterization of liquefaction-prone areas: the Quistello test site, central Po Plain, Northern Italy’, Soil Dynamics and Earthquake Engineering . Giocoli, A. et al. (2014) ‘Electrical resistivity tomography for studying liquefaction induced by the May 2012 Emilia- Romagna earthquake (Mw=6.1, northern Italy)’, Natural Hazards and Earth System Sciences , 14(4), pp. 731– 737. doi: 10.5194/nhess-14-731-2014. Hunter, J. . A. A. (2003) ‘Some observations of Vp, Vs, depth and porosity from borholes in water-satured unconsolidated sediments’, in SAGEEP , pp. 650–661. Ishihara, K. and Tsukamoto, Y. (2004) ‘Cyclic strength of imperfectly saturated sands and analysis of liquefaction’, Proceedings of the Japan Academy, Series B , 80(8), pp. 372–391. doi: 10.2183/pjab.80.372. Jinguuji, M., Kunimatsu, S. and Toprak, S. (2003) ‘A monitoring and visualization technique for liquefaction using resistivity’, in Earthquake Resistant Design of Lifeline Facilities and Countermeasures Against Liquefaction . Robertson, P. K. and Wride, C. (Fear) (1998) ‘Evaluating cyclic liquefaction potential using the cone penetration test’, Canadian Geotechnical Journal . NRC Research Press Ottawa, Canada, 35(3), pp. 442–459. doi: 10.1139/ t98-017. Seed, H. B. and Idriss, I. M. (1971) ‘Simplified Procedure for Evaluating Soil Liquefaction Potential.’, Journal of the Soil Mechanics and Foundations Division , 97(9), pp. 1249–1273. Youd, T. L. and Idriss, I. M. (2001) ‘Liquefaction Resistance of Soils: Summary Report from the 1996 NCEER and 1998 NCEER/NSF Workshops on Evaluation of Liquefaction Resistance of Soils’, Journal of Geotechnical and Geoenvironmental Engineering , 127(4), pp. 297–313. doi: 10.1061/(ASCE)1090-0241(2001)127:4(297). STRUCTURAL JOINT INVERSION OF ELECTRICAL AND SEISMIC TOMOGRAPHY DATA L. Palladini, M. Cercato “Sapienza”, DICEA - University of Rome, Italy Introduction. Groundwater modeling requires the knowledge of aquifer properties, generally derived from direct sampling and laboratory experiments, which are only capable of investigating small volumes of soils and cannot represent the on-site conditions (due to scaling effects,