Geological Model Influence on Slope Stability: Torrioni di Rialba Case Study

ABSTRACT: Landslides are among the most destructive types of natural disasters that can cause significant loss of life and property damage within their zone of impact. This paper presents the study on stability of Torrioni di Rialba (Rialba Towers), a 135-m rock cliff located in Abbadia Lariana, northern Italy, during numerically simulated seismic events of different magnitudes. Torrioni di Rialba is located near a narrow corridor, where important lifelines including rail, road and pipes run alongside each other and connects the northern part of Lombardy to the rest of the country. The study adopted Discrete Element Method (DEM), using Itasca 3DEC, to model the mechanics of the rock cliffs with complex joint orientations, during significant seismic events (with return period of 475 years), recorded in northern Italy. Sensitivity analyses were conducted on key input parameters. The results suggested that the dominant possible slope failure mechanism was sliding of the towers along the dip direction of the slope towards Lake Como. The results show high sensitivity to joint properties while remain less sensitive to intact rock properties.