VS,30 Determinations using MASW for PSHA in Portugal

The Probabilistic Seismic Hazard Map of Portugal is being prepared under the project SCENE – “Site Condition Evaluation for National Seismic Hazard Estimation”. The project is developing a VS,30 database for Portugal, which started by gathering the geologic; geotechnical and geophysical data available in the literature. The detailed geologic and seismic characterization of 30 sites of the Portuguese strong motion network. The sites to be characterized are mainly concentrated in the southern area of Portugal because of the higher site effects felt in these regions in previous earthquakes. The Tagus valley and the Algarve are the areas to be studied in more detail. MASW testing was used in 7 strong-motion sites, mainly to characterize the sites with soft soils (Holocene and Pliocene deposits). Some results of MASW VS,30 determinations in the Tagus valley region are presented here.