PSI - Issue 84

Ilaria Catapano et al. / Procedia Structural Integrity 84 (2026) 119–126

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1. Introduction Bridges are an essential part of the transportation infrastructure, and their structural integrity affects safety and operational reliability. These structures are susceptible to damage from natural events, such as landslides, as well as human-made accidents, which can lead to severe consequences, including structural collapse, traffic disruption, and safety issues. Bridge damage depends on several factors, such as the type of natural or anthropic event impacting the infrastructure, as well as the construction materials and their conditions. Specifically, thoroughly assessing landslide risk requires the evaluation of a variety of factors, including the geophysical properties of the soil and the degradation of key structural elements of the bridge, such as its foundations, piers, and abutments. Furthermore, the widespread aging of bridges, combined with a high density of landslides in proximity to transport networks, calls for non-invasive diagnostic strategies capable of jointly addressing structural and geo-hydrological challenges at the scale of both superstructure and substructure (Giocoli et al., in press). Accordingly, in-situ non-destructive tests are increasingly being used for bridge surveys, and recent literature confirms a systematic growth in the use of electromagnetic (EM) techniques, such as Ground Penetrating Radar (GPR) (Daniels, 2007) and Electrical Resistivity Tomography (ERT) (Lapenna and Perrone, 2022). However, bridge surveys are commonly carried out using approaches that vary on a case-by-case basis and often rely on the operator’s judgement and expertise, resulting in a lack of harmonized protocols, which leads to variability in risk assessments. Moreover, the actual effectiveness of each EM technique is strongly influenced by the characteristics of the investigated scenario, the adopted instrumentation, and the user’s experience in data processing and interpretation. The accuracy and reliability of in-situ non-destructive tests are indeed subject to equipment choice, environmental factors, and data interpretation skills (Giocoli et al., in press). Within this framework, the EMILI project “ElectroMagnetic techniques for Investigating Landslide and structural damage due to their Impacts on the bridges” - funded by the FABRE Consortium, aims to improve the understanding and application of EM techniques for the assessment of bridges and their interaction with landslides. In particular, EMILI aims to achieve two specific objectives: a) to provide a systematic analysis of the performance of available remote and in situ EM techniques, and b) to promote technological advancements, with reference to ERT and GPR. The first objective involves a critical and comprehensive review of case studies reported in the literature that address both remote and in situ EM techniques applied to landslides, bridges, and their interaction. The second objective concerns a performance analysis of GPR and ERT for bridge foundation investigations. This paper presents preliminary results from EMILI focusing on the literature review on the use of GPR and ERT on landslides, bridges, and their interactions. It also describes numerical models and advanced data processing strategies, enabling the evaluation of imaging capabilities of ERT and GPR operating in both standard and unconventional measurement configurations for investigating bridge foundations. 2. Material and methods The first part of this work concerns the literature review of the use of GPR and ERT on landslides, bridges, and their interactions. To this end, a dataset of 323 publications on Non-Destructive Testing (NDT) for in-situ assessment of bridges, landslides, and bridge–landslide interactions was compiled for full-text review. The review was carried out in four stages: (1) performing a search query on the Scopus database; (2) screening the search results; (3) conducting bibliometric and systematic analyses; and (4) evaluating the application, limitations, and opportunities for broader adoption of GPR and ERT in the context of bridges, landslides and their interactions. Regarding the imaging capabilities of ERT and GPR, the preliminary numerical models were developed to simulate different geological scenarios and foundation structures. Soil conditions were systematically varied in terms of water content to assess the capabilities and limitations of ERT and GPR in estimating foundation depth and geometry in different scenarios. For this purpose, both conventional (surface) and unconventional (borehole) measurement configurations were considered. Both commercial and open-source software were employed to develop virtual