127676 20241125101157.0 doi 10.1016/j.enggeo.2023.107289 sideral 134734 ART-2023-134734 eng Gutiérrez, Francisco Universidad de Zaragoza (orcid)0000-0002-5407-940X The application of distributed optical fiber sensors (BOTDA) to sinkhole monitoring. Review and the case of a damaging sinkhole in the Ebro Valley evaporite karst (NE Spain) 2023 Access copy available to the general public Unrestricted Distributed optical fiber sensors (DOFS) have been postulated as a suitable technique for long-range monitoring of sinkhole-related subsidence, and possibly for the anticipation of catastrophic collapse (early-warning systems). The strain data published in previous works refer to artificial experiments considering real and virtual cover collapse sinkholes characterized by rapid subsidence and sharp lateral deformation gradients. The influence of the subsidence mechanism (sagging, collapse, suffosion) on the capability of DOFS to satisfactorily detect active subsidence is discussed. Sagging sinkholes with poorly-defined lateral edges, low lateral deformation gradients and slow subsidence are identified as the most challenging scenario. The performance of BOTDA optical fiber for monitoring such type of sagging sinkholes is evaluated in the active Alcalá sinkhole, which affects a flood-control dike creating a high-risk and -uncertainty scenario. This sinkhole shows active subsidence in sections tens of meters long with maximum subsidence rates ranging between 5 and 35 mm/yr. The comparison of vertical displacement data measured by high-precision leveling and the strain recorded by two types of fiber optic cables shows good spatial and temporal correlation. The subsidence sections are captured in the strain profiles by: (1) troughs of negative strain (contraction) in the area affected by subsidence, with the maximum strain associated with the point of most rapid settlement; and (2) lateral ridges of positive values (extension) in the marginal zones. A subsidence acceleration phase associated with a flood is also captured by substantial increments in the strain values. In this challenging scenario, despite the reasonably good spatial and temporal correlation between the displacement and strain data, the unambiguous identification of the active subsidence area with the fiber optic data alone might be difficult. Better results could be obtained improving the monitoring system (e.g., tighter cable-ground coupling) and testing other types of sinkholes with more localized deformation zones and higher subsidence rates. info:eu-repo/grantAgreement/ES/AEI/PID2021-123189NB-I00 info:eu-repo/grantAgreement/ES/DGA/T20-20R info:eu-repo/grantAgreement/ES/MICINN/PRE2018-084240 info:eu-repo/grantAgreement/ES/MINECO/CGL2017-85045-P info:eu-repo/grantAgreement/ES/MINECO/DI-17-09169 info:eu-repo/semantics/openAccess by-nc http://creativecommons.org/licenses/by-nc/3.0/es/ 6.9 2023 GEOSCIENCES, MULTIDISCIPLINARY 16 / 254 = 0.063 2023 Q1 T1 ENGINEERING, GEOLOGICAL 3 / 63 = 0.048 2023 Q1 T1 2.437 2023 Geotechnical Engineering and Engineering Geology 2023 Q1 Geology 2023 Q1 13.7 2023 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Sevil, Jorge Universidad de Zaragoza (orcid)0000-0002-0068-4532 Sevillano, Pascual Universidad de Zaragoza (orcid)0000-0002-4094-3826 Preciado-Garbayo, Javier (orcid)0000-0001-5898-8777 Martínez, Juan J. Martín-López, Sonia González-Herráez, Miguel 2002 385 Universidad de Zaragoza Dpto. Física Aplicada Área Física Aplicada 2000 427 Universidad de Zaragoza Dpto. Ciencias de la Tierra Área Geodinámica Externa 325 (2023), 107289 [13 pp.] Eng. geol. Engineering Geology 0013-7952 3334825 http://zaguan.unizar.es/record/127676/files/texto_completo.pdf Postprint 1524515 http://zaguan.unizar.es/record/127676/files/texto_completo.jpg?subformat=icon icon Postprint oai:zaguan.unizar.es:127676 articulos driver 2024-11-22-12:09:42 ARTICLE