PSI - Issue 64

Annalisa Mele et al. / Procedia Structural Integrity 64 (2024) 1295–1302 A. Mele et al./ Structural Integrity Procedia 00 (2023) 000 – 000

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Keywords: DInSAR; Landslides; Structural Health Monitoring; Reinforced Concrete Buildings; Infills.

1. Introduction In the context of the dynamic interplay between natural landscapes and human settlements, the study of landslides and their impact on structures remains a crucial domain of geotechnical and civil engineering (Mavrouli et al., 2014; Luo et al., 2019). Advancements in remote sensing techniques, particularly Differential Synthetic Aperture Radar Interferometry (DInSAR- Franceschetti et al., 1999), have opened new avenues for monitoring and quantifying ground movements with high precision, as shown in different applications of structural engineering, e.g., Infante et al. (2019), Miano et al. (2022) and Mele et al. (2023). DInSAR has proven to be a very promising tool in this regard, offering a powerful complement to conventional in-situ analysis methods. This research aims to update and refine the study conducted in a previous work, Miano et al., (2021), concerning the effects of a landslide, which has been in a quiescent state since 2012, characterized by slow kinematics with predominantly horizontal movements, on a reinforced concrete (RC) building. The studied region, Moio della Civitella, encompassing the urban centers of Moio and Pellare (Cilento area, Vallo di Diano, and Alburni National Park and Geopark, in Southern Italy), is geomorphologically and geologically complex. This, combined with the climatic pattern of intermittent and variable-intensity rainfall, predispose it to a range of erosional and gravitational phenomena (Guerriero et al., 2019). The building under investigation, presumed to be constructed between the 1960s and 1970s, is located within the upper part of this landslide, so it has been subjected to significant foundation settlements. It presents a rectangular plan, orthogonal reinforced concrete frames, and distinctive masonry infill. This study leverages high-resolution COSMO-SkyMed satellite data, processed using the Coherent Pixels Technique algorithm (Mora et al., 2003). This interdisciplinary study synthesizes data spanning from 2019 to 2022 to assess the cumulative displacements along the horizontal and vertical axes of the affected building, revealing notable shifts that underscore the ongoing geological activity’s influence on man -made structures (Colesanti et al., 2006). The research further explores the consistency of the displacement rates with previous data sets, highlighting the trends and potential accelerations in the movements of the landslide. By utilizing Inverse Distance Weighting (IDW) interpolation and constructing displacement gradient maps, also the directional tendencies of these shifts are shown, crucial practice for identifying areas of maximum differential movement. The integration of remote sensing data with on-the-ground observations underscores the potential of such technologies in the realm of landslide monitoring and risk mitigation. The findings from this comprehensive approach contribute to the field of landslide research, offering insights into the practical applications of DInSAR technology in monitoring slow-moving landslides and their implications for infrastructure. The research aims to highlight the importance of monitoring, predictive modeling, and the development of adaptive engineering practices to mitigate the risks posed by natural phenomena to the built environment. 2. Case study 2.1. Landslide description The landslide affecting the building under investigation falls within the municipality of Moio della Civitella, which consists mainly of two urban centres: Moio and Pellare. The locality is in the Cilento area, Vallo di Diano and Alburni National Park and Geopark, an important naturalistic site in the province of Salerno (Campania Region, Southern Italy). From a geological point of view, the area is affected by a structurally complex formation consisting of argillites with carbonate and arenite intercalations that act as bedrock and a detrital cover with a silty-clayey matrix, which has the name Crete Nere-Saraceno Formation. Moio della Civitella, due to the geomorphological conformation of the predominantly hilly area and the presence of intermittent rainfall of variable intensity and duration is often subject to erosional and gravitational phenomena. These are translational and rotational sliding and sliding that evolve into flows as can be seen in Fusco et al., (2023) (Fig. 1). The landslide under study is an earth flow, in a quiescent state (updated to 2015), with slow kinematics and mainly horizontal movements (Infante et al., 2017).