A Seismic Microzonation Study for Some Areas Around the Mt. Etna Volcano on the East Coast of Sicily, Italy

On the night of December 26th, 2018, a strong earthquake, with a magnitude of 4.9 on the Richter scale, hit the southeastern side of the Mt. Etna Volcano (Sicily), with the epicenter between the Municipalities of Viagrande and Trecastagni. The hypocenter of the strong earthquake was located just 1 km deep and, for this reason, the effects of the shock were greatly amplified on the ground surface. They have been counted not only material damages to churches and buildings, but also 10 injured around the epicenter area. Therefore, an investigation campaign was carried out with the aim of planning the reconstruction of the damaged areas. In situ soil investigations were carried out in order to determine the soil profile and the geotechnical parameters for the area under consideration. Among in situ tests, borings, Down Hole Tests (D-H), Multichannel Analysis Surface Wave Tests (MASW), Seismic Refraction Tomography and Horizontal to Vertical Spectral Ratio Tests (HVSR) were carried out, with the aim to evaluate the soil profile of shear wave velocity (Vs ). Moreover, laboratory tests were carried out on undisturbed samples in the static field: Shear Tests (ST). The results have been grouped and allowed the characterisation of the following soil categories: clay, sandy clay, silica sand, volcanic sand, volcanic rock. The seismic behaviour of these soil categories has been used for the site response analysis and for the seismic microzonation of the studied area.