PSI - Issue 62

Nicola Perilli et al. / Procedia Structural Integrity 62 (2024) 546–552 Nicola Perilli, Massimiliano Lombardi, Nicola Nenci, Nunziante Squeglia, Stefano Stacul / Structural Integrity Procedia 00 (2019) 000 – 000 3

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b) a Recognized slow landslide located downstream the abutment of a bridge, characterized by a retrogressive distribution of the activity, and currently not interacting with the Influence Zone of the abutment. In this case the type of interference should be considered indirect while the extent of the interference will be the Approach Zone until the evolution of the landslide affects the Influence Zone (i.e. the type of interference changes into direct ). A graphical definition of the most common situations is represented in Fig. 1. In this Figure: Case (1) represents a direct type of interference with a Partial (Abutment) extent; Case (2) represents a direct type of interference with a Total extent; Case (3) represents a slow advancing landslide with an indirect type of interference and an extent involving the Approach Zone; Case (4) represents a rapid flow with an indirect type of interference and a Partial extent (Pier).

Fig. 1. Types of landslide-bridge interference and their extent.

2.2. Additional Field Sheet Form for the characterization of Potential Landslides and for the definition of the overall reliability of the assessment The second objective of this work is to provide an Additional Field Sheet Form, to be filled during the Periodic Field Survey, to improve and support the collection of data and make more reliable the identification and characterization of Potential Landslides. To date in all the cases in which the inspector recognizes the presence of a Potential Landslide the current version of LLG strongly recommends selecting the option limited for the overall reliability of the assessment parameter. The proposed Additional Field Sheet Form, divided into three sections (as shown in Tabs. 1, 2 and 3), is necessary for a better evaluation of the landslide susceptibility and allows to select with more confidence the option good for the overall reliability of the assessment parameter. The first section (Tab. 1) of the Additional Field Sheet Form is aimed to collect all the necessary data for the: (a) characterization of the geomorphological and geological context, with a special attention to the topographic