PSI - Issue 62

Nicola Perilli et al. / Procedia Structural Integrity 62 (2024) 546–552 551 6 Nicola Perilli, Massimiliano Lombardi, Nicola Nenci, Nunziante Squeglia, Stefano Stacul / Structural Integrity Procedia 00 (2019) 000 – 000

Table 3. Third section of the Additional Field Sheet Form (this work)

ESTIMATION OF PRIMARY AND SECONDARY PARAMETERS

Expected parameters of the PLS – SUB-SECTION H

Level of criticality Highly critical Critical Not very critical

Velocity

Volume

> 3 m/min 3 m/min – 1,8 m/h 1,8 m/h – 13 m/month

13 m/month – 1,6 m/year < 1,6 m/year not assessable

Area Maximum length Maximum width

Crown altitude Foot altitude Depth bedrock

Evaluation of the magnitude (m 3 ) of the PLS – SUB-SECTION I

Trunks (%) Tree branches (%) Shrubs (%)

Fractures units Mass rocks (%)

Stratified units

Rock-dominant (%)

Pelitic-dominant (%)

Granulometry (%)

Clasts (%)

Classification

Trunks (N°) h > 30 m: h = 20-30 m: h = 10-20 m: h < 10 m:

Volume of vegetation cover (m 3 )

d > 2 m d = 0,6 – 2 m d = 0,2 – 0,6 m d = 60 – 200 mm

Coarse (> 2 mm) Fine (< 2 mm)

Debris flow Mud flow

3. Conclusions Considering the requirement of the LLG about the accurate identification and characterization of Potential Landslides, (i.e., an appropriate characterization of the geomorphological and the geological context, and of the mechanical properties of the materials) the Additional Field Sheet Form will (1) support the inspector in the collection of data easily-recognizable, and (2) contribute to reduce the arbitrariness, in the evaluation of parameters, and in particular of the extent of the interference and overall reliability of the assessment . The suggested definitions of direct and indirect landslide-bridge interferences, based on an appropriate definition of Influence Zone and Approach Zone , will permit a more accurate selection of the options for the extent of the interference parameter. Furthermore, considering that the assessment of both the type and the extent of the interference is a challenge also for Recognized Landslides, the Authors recommend always filling, during the Periodic Field Survey, the here presented Additional Field Sheet Form. The data of the Additional Field Sheet Form, necessary to characterize Potential Landslides, are also useful to characterize Recognized Landslides, and to define the overall reliability of the assessment parameter. The subclasses and subcategories introduced in the Additional Field Sheet Form will permit to accurately characterize the context and the source areas that can generate Potential Landslides and will significantly increase the quality and the quantity of the collected data. Furthermore, standardizing both the collection of data and its uploading into a database it will facilitate interactions between operator and database even during the query phase. In summary, compared to some sheets found in the literature to identify and characterize Landslides, the proposed Additional Field Sheet Form is consistent with the path traced by the LLG, because it is based on the collection of data clusters easily available by the technical staff in charge of the Periodic Field Survey. The Authors work and the Additional Field Sheet Form presented herein are of course not the point of arrival but the starting point for a deeper discussion (with the other teams involved in the application of the LLG) aimed to define the best tools to be adopted for a reliable assessment of the Landslide Class of Attention. Acknowledgements This research was supported by FABRE “Research consortium for the evaluation and monitoring of bridges, viaducts, and other structures” (https://www.consorziofabre.it/). References Ministry for Sustainable Infrastructure and Mobility (MIMS), 2022. Ministerial Decree 204 on 01.07.2022. Guidelines for the Classification and Management of Risk, the Safety Assessment and the Monitoring of Existing Bridges. Italy. G.U. Serie Generale n.196, 23-08-2022. Norme Tecniche per le Costruzioni, NTC, 2018. Gazzetta Ufficiale, n. 42 del 20/02/2018, Supplemento ordinario n.8 [in Italian].