Seismic soil classification of Italy based on surface geology and shear-wave velocity measurements

• Published in: Soil dynamics and earthquake engineering (1984) Vol. 122; pp. 79 - 93
• Main Authors: Forte, Giovanni, Chioccarelli, Eugenio, De Falco, Melania, Cito, Pasquale, Santo, Antonio, Iervolino, Iunio
• Format: Journal Article
• Language: English
• Published: Barking Elsevier Ltd 01.07.2019; Elsevier BV
• Subjects: Bedrock; Earthquakes; Environmental risk; Geological mapping; Geology; Ground motion; Lithology; Probabilistic seismic hazard assessment; Regional seismic risk; Seismic activity; Seismic hazard; Seismic soil response; Seismic waves; Shear; Site classification; Soil characteristics; Soil classes; Soil classification; Soil investigations; Soil maps; Territory; Velocity; Wave amplification; Wave velocity; Italy; Soil classes; Seismic soil response; Probabilistic seismic hazard assessment; Regional seismic risk; Site classification
• ISSN: 0267-7261; 1879-341X
• DOI: 10.1016/j.soildyn.2019.04.002

During an earthquake the seismic wave amplification related to local site conditions can have a significant impact on the ground motion. In order to account for these local effects some proxies for the soil characteristics exist; e.g., the average shear-wave velocity of the upper 30 m (VS,30), or the equivalent shear-wave velocity from the ground to the depth of the seismic bedrock when this is less than 30 m VS,eq. The aim of this paper is to provide maps of seismic shallow soil classification for Italy accounting for two sources of information: site-specific measurements and large-scale geological maps. The soil maps are obtained via a four-step procedure: (1) a database of available site-specific investigations is built, covering (unevenly) the whole national territory; (2) twenty geo-lithological complexes are identified from the available geological maps; (3) the investigations are grouped as a function of the geo-lithological complex and the distribution of measured VS,30 and VS,eq are estimated; (4) medians and standard deviations of such distributions are assumed to be representative of the corresponding complexes. The statistics of investigations are used to derive the large-scale soil maps. To make the results of the study available, a stand-alone software has been developed. Despite not being adequate substitutes of site-specific studies such as microzonation and local site response analyses, the provided results can be useful for large-scale seismic risk studies. •Procedure for correlating surface geological maps and Vs measurements.•Maps of large-scale seismic soil classification for Italy.•Site classification according to EC8 and ItBC2018.•Stand-alone software for database interrogation.