Site effects characterization in Lorca city

Abstract

This study is focused on the characterization of seismic local effects in Lorca city. This aspect fits to one of the interesting points of a field survey for a post-seismic inspection organized by Institut Geològic of Catalonia (IGC), the Universitat Politècnica of Catalonia (UPC), the Spanish Association of Seismic Engineering (AEIS) together with the Earthquake Engineering Associations of France (AFPS) and Portugal (SPES) with the aim to calibrate, check and validate methodologies for seismic risk assessment that these organisms use. We present the work done and the obtained results in order to characterize the soil layers applying two passive seismic techniques: the H/V spectral ratio and the array method. The record of aftershocks in different emplacements has allowed us to obtain the soil seismic response of these sites. The information obtained from the geophysical field survey allowed the definition of representative soil columns and the soil classification according the Eurocode 8. Subsequently, the soil seismic response has been modelled and the increase of macroseismic intensity due to the presence of soft soils has been assessed.