GNGTS 2023 - Atti del 41° Convegno Nazionale

Session 2.1 GNGTS 2023 (s2) Basalts and andesites (San Salvador formation) – soft rock 22 40 200 (b3) Basalts and andesites (Balsamo formation) - hard rock 26 45 300 From the literature, the landslides induced by the 13 January 2001 earthquake show a depth of the sliding surface less than 10 m (Conrad and Bommer, 2001; Bommer et al., 2002; Jibson et al., 2004). Accordingly, in the present study, 10 m depth has been assumed for the calculation of the permanent displacements. Finally, the classification by García-Rodríguez et al. (2007) of the physical and mechanical properties of the lithotypes are summarized in Table 1 and used in the calculations. Permanent displacements calculated following a GIS-based approach A common method to calculate, at regional scale, the permanent displacements induced by seismic events is to use regression equations drawn from databases of records of seismic accelerations from different seismic events worldwide. These equations use seismic parameters (such as PGA, PGV and I a ) and dynamic resistance variable like the critical acceleration (k c ) based on the Mohr-Coulomb resistance criterion for soils, to estimate the expected seismic displacements at the site of interest (Vessia et al., 2013). In this study, two formulations have been selected to draw maps of D triggered by the 13 January 2001 earthquake within Qgis environment: (cm) (1) ( ) = 0. 561 * log ( ) − 3. 833 * log ( ) − 1. 474±0. 616 ( ) =− 0. 22 − 2. 83 * ln ( ) − 0. 333(ln ( ) 2 + 0. 566 * ln ( ) * ln ( ) + 3. 04 * ln ( ) + 0. 244 * ln ( ) 2 + 0. 278 * ( − 7)±0. 67 (cm) (2) Eq. (1) was proposed by Jibson (2007), Eq. (2) by Bray and Travasarou (2007), where I a is the Arias Intensity; k c is the critical seismic acceleration; PGA is the peak ground acceleration; M is the Magnitude. The spatial interpolation of PGA and PGV have been performed by the Digital Terrain Model (DTM) of 5x5 m 2 provided by the Ministerio de Medio Ambiente y Recursos Naturales (MARN) Office. The DTM has been Geo-Referred through the projected coordinate system WGS 84 / UTM zone 16N EPSG:32616.