Topographic Effects of the Monte Po Hill in Catania

The study is related to the evaluation of site effects in correspondence of the Monte Po hill, located in the north-eastern part of the city of Catania (Italy), which is an area at high seismic risk. In the beginning of 2007 a seismic station has been located into a school building, situated at the slope toe, but no seismic events have been yet recorded. Seismograms obtained by the seismic station have been also used to evaluate the ground response analysis at the surface. Because the slope is moderate (less than 15°), 1-D computer codes have been used to model the equivalent-linear earthquake site response analyses of layered soil deposits of the hill, as general performed by professionals. However the slope response was analysed in more detail, using a 2-D computer code. Also soil characterization have been evaluated accurately by means of borings, Down-Hole tests, SDMT tests and laboratory tests. Comparing 1-D with 2-D results it has been also computed the stratigraphic site amplification and the topographic amplification (TAF). The study has been performed as a basis for the design of the remedial works for damages caused by the landslide reactivated by the December 13, 1990 Sicilian earthquake (ML= 5.4).