Integrated approach to the analysis of earthquake-triggered landslides and their impact on road infrastructures

This thesis dealt with one of the side-phenomena, which can occur during or after a seismic event, namely earthquake-triggered landslides. These phenomena involve both natural and man- made slopes, whose occurrence is very common and widespread as testified by several recent earthquakes. Their consequences can be dramatic, as they can strongly contribute to the death toll, since they often affect buildings and infrastructures, preventing effective post-emergency strategies. Hence it appears relevant to consider into the framework of seismic risk studies also the evaluation of slope stability, which can also be carried out from regional to the scale of the single slope. The area selected for the present study is the Molise Region, (Central-Southern Italy) within the Southern Apennines, which is one of the Italian areas struck by earthquakes in the last decade, suffering damages both in building heritage and physical environment. It is characterized by medium-high seismicity and high landslide susceptibility. In particular, the most abundant landslides are represented by coherent landslides, i.e. rotational and translative slides, on which this dissertation focused. The main issues concerned the development of stability analysis at territorial scale; within this framework several side-issues were explored. In particular, the implementation of a database of geological and geotechnical tests permitted to characterize the soil strength behavior, produce seismic soil class map and empirical correlations between geotechnical parameters. The stability analyses were calculated as PGD at regional scale through two methodologies, which found validation in the detailed analysis of a case study.