Influence of the Geometry Alteration of the Landslide Slope on its Stability: A Case Study in the Carnian Alps (Italy)

Abstract The paper presents the principles of the slope reprofiling and proves the effectiveness of this stabilization measure. The case study of two adjacent landslides in the National Road 52 “Carnica” in the Tagliamento River valley, the Carnian Alps (46°23′49″N, 12°42′51″E) are the example allowing for illustration of this approach. The phenomena have been studied for more than a decade, making it possible to carry out a detailed geological and geomorphological reconstruction. That was done on the basis of a large amount of monitoring data collected during that period. Since the landslides are threatening an important road, countermeasure works to ameliorate the stability conditions of the slides need to be designed. The paper focuses on the creation of a numerical model consistent with monitoring data and capable of reconstructing the dynamics of both landslides. Two cross-sections, one for each landslide, were selected for the analysis. The geometry of the slip surface was determined on the basis of control points, such as slip surface readings from inclinometers, and geomorphological evidence for the contour. The FLAC2D code was used to evaluate the current stability of these landslides and to determine the effectiveness of changing the slope geometry by removing material from the upper part of the slope and putting it to the lowest part as reinforcement.