Determination of the stability conditions of a rock slope using an integrated geological, geomorphological and lithotechnical approach: the example of Bolognana (Lucca - Italy)

The slope of the Costa delle Calde is affected by numerous gravitational mass movements, both active and of large dimensions. In this study its present conditions of stability are evaluated. The various tools of inquiry made it possible to recognize the formations and lithotypes present along the slope, provide a general picture of the complex structure of the slope and identify the forms, deposits and processes, superficial and deep, due both to gravity and to the action of the surface flowing waters. Moreover, the outcropping formations and the covers were characterized from a lithologic-technical point of view, in an analysis whose aim was the identification of classes with homogeneous geomechanical characteristics. The structure of the rock masses and the complex network of discontinuities present within them were examined. In the situations considered most critical, in particular along the valley main road, possible kinematics, deriving from the sliding of rock wedges, were analyzed. From these data it was possible to assess the geomechanical characteristics and the conditions of the rock masses that constitute this slope. We believe that the data in question, appropriately modified for comparison with the climatic elements, can contribute to the definition of landslide hazard in this area.