Evaluation of Soil-Building Interaction in the Urban Area of Matera City (Southern Italy)

In this research we propose a new method to include the presence of buildings in microzonation studies in order to evaluate the urban built environment as a complex soil-buildings system according a holistic approach. Taking into account the resonance effect between buildings and soils, this approach could overcome the intrinsic limitations of the microzonation studies making it even more robust and useful for an appropriate territorial planning and rational allocation of interventions.

230 single station ambient seismic noise measurements were performed in the urban area of the Matera city (Southern Italy): 134 on the main lytologies and 96 on the principal building typologies. The measures on soils allowed us to estimate the soil fundamental frequencies of the whole urban area and those on buildings their main periods. The fundamental frequencies of all the Matera's buildings have been estimated by using the experimental period-height (T-H) relationship for the monitored buildings and a database containing information about height, use, age and typology for all buildings. It was therefore possible to assign a resonance level for each building with the relative foundation soil, thus obtaining a soil-building resonance map in the linear elastic domain. This spatial information is an extremely important element as it allows us to understand the most dangerous areas of the city, i.e. where much more likely the effect of soil-building resonance effect can cause an increase in damage during earthquakes. Because the buildings represent an extremely important element in the urban areas we believe that the interaction effect between building and soil should definitely be implemented in microzonation studies as it would allow a more appropriate territorial planning and rational allocation of interventions.