{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T20:12:04Z","timestamp":1770840724730,"version":"3.50.1"},"reference-count":35,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2021,10,23]],"date-time":"2021-10-23T00:00:00Z","timestamp":1634947200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100003407","name":"Ministry of Education, Universities and Research","doi-asserted-by":"publisher","award":["project MITIGO, ARS01_00964"],"award-info":[{"award-number":["project MITIGO, ARS01_00964"]}],"id":[{"id":"10.13039\/501100003407","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper shows the results of the monitoring of the deformations of a tunnel, carried out using a distributed optical fiber strain sensor based on stimulated Brillouin scattering. The artificial tunnel of the national railway crosses the accumulation zone of an active landslide, the Varco d\u2019Izzo earthflow, in the southern Italian Apennines. Severely damaged by the landslide movements, the tunnel was demolished and rebuilt in 1992 as a reinforced concrete box flanked by two deep sheet pile walls. In order to detect the onset of potentially dangerous strains of the tunnel structure and follow their time trend, the internal deformations of the tunnel are also monitored by a distributed fiber-optic strain sensor since 2016. The results of the monitoring activity show that the deformation profiles are characterized by strain peaks in correspondence of the structural joints. Furthermore, the elongation of the fiber strands crossing the joints is consistent with the data derived by other measurement systems. Experiments revealed an increase in the time rate of the fiber deformation in the first and last part of the monitoring period when the inclinometers of the area also recorded an acceleration in the landslide movements.<\/jats:p>","DOI":"10.3390\/s21217032","type":"journal-article","created":{"date-parts":[[2021,10,24]],"date-time":"2021-10-24T22:07:11Z","timestamp":1635113231000},"page":"7032","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":15,"title":["Long-Term Monitoring of a Tunnel in a Landslide Prone Area by Brillouin-Based Distributed Optical Fiber Sensors"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-8966-9143","authenticated-orcid":false,"given":"Aldo","family":"Minardo","sequence":"first","affiliation":[{"name":"Department of Engineering, University of Campania \u201cLuigi Vanvitelli\u201d, 81031 Aversa, Italy"}]},{"given":"Ester","family":"Catalano","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Campania \u201cLuigi Vanvitelli\u201d, 81031 Aversa, Italy"}]},{"given":"Agnese","family":"Coscetta","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Campania \u201cLuigi Vanvitelli\u201d, 81031 Aversa, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5701-5228","authenticated-orcid":false,"given":"Giovanni","family":"Zeni","sequence":"additional","affiliation":[{"name":"Institute for Electromagnetic Sensing of the Environment, Italian National Research Council, 80124 Naples, Italy"}]},{"given":"Caterina","family":"Di Maio","sequence":"additional","affiliation":[{"name":"School of Engineering, University of Basilicata, 85100 Potenza, Italy"}]},{"given":"Roberto","family":"Vassallo","sequence":"additional","affiliation":[{"name":"School of Engineering, University of Basilicata, 85100 Potenza, Italy"}]},{"given":"Luciano","family":"Picarelli","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Campania \u201cLuigi Vanvitelli\u201d, 81031 Aversa, Italy"}]},{"given":"Roberto","family":"Coviello","sequence":"additional","affiliation":[{"name":"Rete Ferroviaria Italiana (Ferrovie dello Stato Italiane Group), 70122 Bari, Italy"}]},{"given":"Giuseppe","family":"Macchia","sequence":"additional","affiliation":[{"name":"Rete Ferroviaria Italiana (Ferrovie dello Stato Italiane Group), 70122 Bari, Italy"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8356-7480","authenticated-orcid":false,"given":"Luigi","family":"Zeni","sequence":"additional","affiliation":[{"name":"Department of Engineering, University of Campania \u201cLuigi Vanvitelli\u201d, 81031 Aversa, Italy"}]}],"member":"1968","published-online":{"date-parts":[[2021,10,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"268","DOI":"10.1007\/s13320-011-0011-x","article-title":"Fiber-optic sensor applications in civil and geotechnical engineering","volume":"1","author":"Habel","year":"2011","journal-title":"Photonics Sens."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"131","DOI":"10.1016\/j.sna.2017.03.017","article-title":"Recent progress of using Brillouin distributed fiber optic sensors for geotechnical health monitoring","volume":"258","author":"Hong","year":"2017","journal-title":"Sens. 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