PSI - Issue 62

Diana Salciarini et al. / Procedia Structural Integrity 62 (2024) 514–521 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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The primary aim of the study is to evaluate the consequences of the impact of landslide phenomena on these structures. To achieve this objective, a detailed classification of the collected information was performed, considering various factors including the construction characteristics of the bridges or viaducts, the type of interaction with the landslide phenomenon, the direction of the landslide movement, and the kind of damage incurred on the infrastructure caused by landslides. This classification allowed a detailed and accurate understanding of the most common situations in scenarios of this kind, thereby providing a clear picture of the circumstances that mostly influence the infrastructure response to such events. Through statistical analysis of the data, it was possible to correlate different factors with each other, emphasizing particularly the types of damage sustained by the structures due to landslides. It emerged that in most cases where there is a complete interaction between the landslide phenomenon and the infrastructure, this leads to a total collapse of the structure (Fig.3). Conversely, situations of partial interference, such as limited impacts on the piers or abutments, resulted in total collapses with a substantially lower frequency. Another important aspect that emerged from the analysis was the influence of the landslide direction in determining the nature of the damage. Landslides impacting the structure orthogonally tend, in most cases, to cause total collapses. In contrast, when the landslide occurs parallel to the structure, partial collapses are more common. This analysis, therefore, underscored the importance of considering the direction of the landslide when assessing risks to infrastructures. The analysis also allowed a better understanding of the factors determining the structural response in the presence of landslide phenomena, highlighting the circumstances in which structures are more at risk of severe damage or collapse.

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Fig. 3. Distribution of percentages of a) level of damage vs . type of interaction; b) level of damage vs . landslide direction.

3. Numerical modelling Following the analysis of case studies related to bridges and viaducts interacting with landslide phenomena, as previously outlined, a three-dimensional model was developed to simulate the rotational movement of a seismic-induced landslide on a gentle slope. This model was implemented using Plaxis 3D software (Brinkgreve et al., 2016). The considered soil volume has dimensions of 250 x 250 m and a height of 90 m. Additionally, the model includes an ideal landslide subject to rotational sliding, characterized by dimensions of 85 x 70 m and a sliding surface depth of 12 m (see Fig. 4).