ABSTRACT:
The San Bartolo Cliff extends along the Italian Adriatic coast for about 12 km in a WNW direction between Pesaro and Gabicce. The coastal relief mainly consists of marine sediments composed of weakly interbedded cemented sandstones and marls. The sea cliff is subjected to localized complex instability phenomena causing issues with buildings and infrastructure close to the slope crest. A study of the temporal evolution of displacements based on aerial photographs was performed. Slope movements on a cross section of the sea cliff were back-analysed using the finite difference code FLAC. The rock mass parameter assessment was made in accordance with the Geological Strength Index classification for heterogeneous rock mass and the Hoek-Brown failure criterion was implemented in the computer code.
1 INTRODUCTION
The Colle San Bartolo Cliff extends along the Adriatic coast for about 12 km in a WNW direction between Pesaro and Gabicce (Italy). This is the first stretch of cliffs along the Adriatic coastline south of Trieste. It reaches its maximum heights at the towns of Casteldimezzo (195m a.s.l.) and Fiorenzuola di Focara (186m a.s.l.). This area is the location of the San Bartolo Regional Nature Park, a protected area with many natural attractions such as rare animal and plant species. According to the Directive 79/409/CEE (Preservation of wild birds), the Colle San Bartolo Cliff has also been identified as a Zone of Special Protection (ZPS). The sea cliff was formed in sedimentary rocks of Neogene age. The sediments consist of pelitic layers alternated with lapideous (calcareous and arenaceous) components. The complex structure of the deformed bedrock has been modeled by diastrophism: folds are cut by faults and discontinuities, from the smaller to the larger scales, are clearly visible along the slopes. Alternating strata with contrasting geomechanical properties characterize the slope.
