Antonio Cavallaro

Geotechnical Aspects of the L’Aquila Earthquake

On April 6, 2009 an earthquake (ML = 5.8 and MW = 6.3) stroke the city of L’Aquila with MCS Intensity I = IX and the surrounding villages with I as high as XI. The earthquake was generated by a normal fault with a maximum vertical dislocation of 25 cm and hypocentral depth of about 8.8 km. The deaths were about 300, the injured were about 1,500 and the damage was estimated as high as about 25 billion €. Both maximum horizontal and vertical components of the accelerations recorded in the epicentral area were close to 0.65 g. The paper summarises the activities in the field of earthquake geotechnical engineering aimed to the emergency and reconstruction issues. The ground motion recorded in the epicentral area is analysed; the geotechnical properties measured by in-situ and laboratory tests before and after the earthquake are summarised; site effects are preliminarily evaluated at accelerometric stations locations and damaged villages; the outstanding cases of ground failure are finally shown.

A case-study (The Saint Nicolò Cathedral) for dynamic characterization of soil from in situ and laboratory tests

The Saint Nicolo Cathedral of Noto was damaged by a post-seismic structural collapse on March 13th 1996 and is now under repair and restoration. The city of Noto is located near Siracusa on the east coast of Sicily and actually is object of a seismic microzonation (level II) study. Assessment of the seismic risk of Saint Nicolo Cathedral by means of analytical computation is also under way. To this end, in situ and laboratory investigations have been carried out in order to determine the soil profile with special attention being paid to the variation of shear modulus and damping ratio with depth. This paper is aimed at providing information about the Saint Nicolo Cathedral site characterisation for seismic analysis.