GNGTS 2018 - 37° Convegno Nazionale

GNGTS 2018 S essione 3.2 633 the 2.5 Hz frequency could be due to the contrast between the sands and underlying clays while the 1.5 Hz frequency could be originated by the clays and the bedrock which is characterized by the conglomerate unit. The directional analysis of the three HVNSR functions shows that both resonance peaks of the deformation phenomenon have a directionality of approximately 30° respect to the main axis of the deformation area. The HVSR function estimated in the area of the failure (AV2 in Fig. 3), from the analysis of earthquake recordings on the ground floor of the building affected by the structural damage, do not show any particular resonance peaks. It is therefore assumed that the presence of substructures and containment works in the area below did not allow a correct estimate of the site seismic response. Conclusions. The approach proposed is based on the integration of satellite and in-situ geophysical techniques. The top-down philosophy adopted proved to be suitable to locate sites affected by ground deformation and to reconstruct the litho-stratigraphic and geometrical details in the investigated area. Minimum invasiveness, low costs and rapidity of the measures represent an added value of the proposed approach. The lack of indications regarding the possible causes of the processes causing the ground deformation made not possible to verify whether the deformation was due to the compaction of filling material or to a hydrogeological phenomenon. A better understanding of the processes involved would require the acquisition of additional information, such as piezometric and inclinometric measurements, rain-gauge data, etc. References Bonano M., Manunta M., Marsella M., Lanari R.; 2012: Long-term ERS/ENVISAT deformation time-series generation at full spatial resolution via the extended SBAS technique . Int. J. Remote Sens. 33 :4756–4783. Calamita G., Serlenga V., Stabile T.A., Gallipoli M.R., Bellanova J., Bonano M., Casu F., Vignola L., Piscitelli S., PerroneA.; 2018: An integrated geophysical approach for urban underground characterization: the Avigliano town (southern Italy) case study . Journal: Geomatics, Natural Hazards andRisk, DOI: 10.1080/19475705.2018.1526220. Gallipoli M.R., Mucciarelli M., Vona M.; 2009: Empirical estimate of fundamental frequencies and damping for Italian buildings . Earthq. Eng. Struc. Dyn. 38 (8): 973-988. Kuras O., Wilkinson P.B., Meldrum P.I., Oxby L.S., Uhlemann S., Chambers J.E., Binley A., Graham J., Smith N.T., Atherton N.; 2016: Geoelectrical monitoring of simulated subsurface leakage to support high-hazard Fig. 3 - [a] ERT1 (first and last electrodes are located at 0 m and 185.5 respectively) with stratigraphic data (D10); [b] mean HVNSR (HV11, HV10 e HV2) and HVSR (AV2); [c] directional HVNSR, [d] the depth Vs profile and (e) the dispersion curve obtained by the MASW survey along Viale della Vittoria in the urban center of Avigliano (PZ, Italy). Black arrows point to the limits of the differential failures.