Long-term analysis of ERT monitoring data measured on a critical slope above a high-speed railway gallery

Article Sidebar

PDF
Published: 2025-08-21
DOI: https://doi.org/10.4401/ag-9235

Main Article Content

Azadeh Hojat
Politecnico di Milano, Dipartimento di Ingegneria Civile e Ambientale and Shahid Bahonar University of Kerman, Department of Mining Engineering, Kerman, Iran
Greta Tresoldi
LSI LASTEM, Settala (MI)
Regina Bianchi
Politecnico di Milano, Dipartimento di Ingegneria Civile e Ambientale
Federica Brambilla
Politecnico di Milano, Dipartimento di Ingegneria Civile e Ambientale
Luigi Zanzi
Politecnico di Milano, Dipartimento di Ingegneria Civile e Ambientale

Abstract

A customized electrical resistivity tomography (ERT) monitoring system was installed on a critical slope above a high-speed railway gallery in March 2022 to monitor the stability condition of the slope. We discuss the results of long-term analysis of the data measured by the system from 24 March 2022 until 21 September 2023. Initial data quality checks were performed to control the quality of the data measured during day and night. We then discuss the optimization of the time-lapse inversion algorithm to generate artifact-free ERT images that can reflect the real distribution of the water content. Using meteorological data, the site-specific model for seasonal variations of the soil temperature at different depths was calibrated and the corresponding resistivity corrections were applied to suppress the effects induced by temperature variations that showed to be important only down to 6 m. Five piezometers were installed along the ERT profile to monitor the water table fluctuations and to correlate the inverted resistivities with piezometric measurements. The complex geology of the site and the complex response of the piezometers to rainfalls suggested focusing the analysis on two target zones identified on ERT images rather than analyzing the average behavior of the resistivity versus the average behavior of the piezometers. A scatterplot for one of these zones, apparently the most sensitive zone to rainfalls and water saturation, was obtained from long-term analysis of the ERT data integrated with the piezometric levels and  we could establish a preliminary threshold for addressing excessive water content in this area.

Article Details

Issue

Vol. 68 No. 3 (2025): SPECIAL ISSUE: Geophysical site characterization for geotechnical studies: current practices and future developments

Section

SPECIAL ISSUE: Geophysical Site Characterization for geotechnical studies: current practices and future developments
Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Open-Access License

No Permission Required

Istituto Nazionale di Geofisica e Vulcanologia applies the Creative Commons Attribution License (CCAL) to all works we publish.

Creative Commons License

Under the CCAL, authors retain ownership of the copyright for their article, but authors allow anyone to download, reuse, reprint, modify, distribute, so long as the original authors and source are cited. No permission is required from the authors or the publishers.

In most cases, appropriate attribution can be provided by simply citing the original article.
If the item you plan to reuse is not part of a published article (e.g., a featured issue image), then please indicate the originator of the work, and the volume, issue, and date of the journal in which the item appeared. For any reuse or redistribution of a work, you must also make clear the license terms under which the work was published.
This broad license was developed to facilitate open access to, and free use of, original works of all types. Applying this standard license to your own work will ensure your right to make your work freely and openly available. For queries about the license, please contact ann.geophys@ingv.it.

 

How to Cite

(1)
Hojat, A.; Tresoldi, G. .; Bianchi, R. .; Brambilla, F. .; Zanzi, L. . Long-Term Analysis of ERT Monitoring Data Measured on a Critical Slope above a High-Speed Railway Gallery. Ann. Geophys. 2025, 68 (3), NS335. https://doi.org/10.4401/ag-9235.