Quantitative risk analysis for earthquake-induced landslides—Emamzadeh Ali, Iran

Earthquake-induced landslides are among the most destructive slope movements, not only because of their size and magnitude, but also because of the synergistic action with the earthquake the consequences are higher, due to the earthquake shaking and the landslide effect. Studies on landslides triggered by seismic activities are not as extensive as rainfall-induced landslides.In this study, a quantitative risk analysis approach was used to calculate the risk for people exposed to the threat of earthquake-induced landslide in Emamzadeh Ali, north of Iran. Emamzadeh Ali was selected as it has already experienced some landslides and is located in a tectonically active region.A numerical model was used in this study to carry out the stability analysis of the slope, under both static and dynamic conditions. A quantitative probabilistic approach was developed for determining the frequency and magnitude of the process. In addition, the values of vulnerability for each building were calculated. The highest risks (individual risk to life and societal risk to life) are in the area of the stone mine on the head of the slope and close to the toppling activities north-east of the study area.

► A seismic hazard analysis was used to determine the frequency of earthquake as a triggering factor of landslide. ► A dynamic stability analysis was used to determine the threshold of a slope movement. ► The calculated Newmark displacement for Emamzadeh Ali slope in this study shows a complete failure of the slope. ► Using the Seismic Hazard Curve, the probability of occurrence of an earthquake with a PGA of 0.37g is equal to 0.001. ► The highest risks in the analyses are for the area of the stone mine on the head of the slope.