View in EDS

Monitoring of Älvkarleby test embankment dam using 3D electrical resistivity tomography for detection of internal defects

Saved in:
Bibliographic Details
Title: Monitoring of Älvkarleby test embankment dam using 3D electrical resistivity tomography for detection of internal defects
Authors: Norooz, Reyhaneh, Nivorlis, Aristeidis, Olsson, Per Ivar, Günther, Thomas, Bernstone, Christian, Dahlin, Torleif
Contributors: Lund University, Faculty of Engineering, LTH, Departments at LTH, Department of Biomedical Engineering, Division of Engineering Geology, Lunds universitet, Lunds Tekniska Högskola, Institutioner vid LTH, Institutionen för biomedicinsk teknik, Avdelningen för teknisk geologi, Originator, Lund University, Faculty of Engineering, LTH, LTH Profile areas, LTH Profile Area: The Energy Transition, Lunds universitet, Lunds Tekniska Högskola, LTH profilområden, LTH profilområde: Energiomställningen, Originator, Lund University, Faculty of Engineering, LTH, LTH Profile areas, LTH Profile Area: Water, Lunds universitet, Lunds Tekniska Högskola, LTH profilområden, LTH profilområde: Vatten, Originator
Source: Journal of Civil Structural Health Monitoring. 14(5):1275-1294
Subject Terms: Engineering and Technology, Civil Engineering, Geotechnical Engineering and Engineering Geology, Teknik, Samhällsbyggnadsteknik, Geoteknik och teknisk geologi
Description: Electrical resistivity tomography (ERT) is a potential-based method for detecting internal erosion in the core of embankment dams using the electrodes installed outside. This study aims at evaluating the practical capability of ERT monitoring for detecting internal defects in embankment dams. A test embankment dam with in-built well-defined defects was built in Älvkarleby, Sweden, to assess different monitoring systems including ERT and the defect locations were unknown to the monitoring teams. Between 7500 and 14,000 ERT data points were acquired daily, which were used to create the distribution of electrical resistivity models of the dam using 3D time-lapse inversion. The inversion models revealed a layered resistivity structure in the core that might be related to variations in water content or unintentional variations in material properties. Several anomalous zones that were not associated with the defects were detected, which might be caused by unintentional variations in material properties, temperature, water content, or other installations. The results located two out of five defects in the core, horizontal and vertical crushed rock zones, with a slight location shift for the horizontal zone. The concrete block defect in the core was indicated, although not as distinctly and with a lateral shift. The two remaining defects in the core, a crushed rock zone at the abutment and a wooden block and a crushed rock zone in the filter, were not discovered. The results cannot be used to fully evaluate the capability of ERT in detecting internal erosion under typical Swedish conditions due to limited seepage associated with the defects. Furthermore, scale effects need to be considered for larger dams.
Access URL: https://doi.org/10.1007/s13349-024-00785-x
Database: SwePub
Description
Abstract:Electrical resistivity tomography (ERT) is a potential-based method for detecting internal erosion in the core of embankment dams using the electrodes installed outside. This study aims at evaluating the practical capability of ERT monitoring for detecting internal defects in embankment dams. A test embankment dam with in-built well-defined defects was built in Älvkarleby, Sweden, to assess different monitoring systems including ERT and the defect locations were unknown to the monitoring teams. Between 7500 and 14,000 ERT data points were acquired daily, which were used to create the distribution of electrical resistivity models of the dam using 3D time-lapse inversion. The inversion models revealed a layered resistivity structure in the core that might be related to variations in water content or unintentional variations in material properties. Several anomalous zones that were not associated with the defects were detected, which might be caused by unintentional variations in material properties, temperature, water content, or other installations. The results located two out of five defects in the core, horizontal and vertical crushed rock zones, with a slight location shift for the horizontal zone. The concrete block defect in the core was indicated, although not as distinctly and with a lateral shift. The two remaining defects in the core, a crushed rock zone at the abutment and a wooden block and a crushed rock zone in the filter, were not discovered. The results cannot be used to fully evaluate the capability of ERT in detecting internal erosion under typical Swedish conditions due to limited seepage associated with the defects. Furthermore, scale effects need to be considered for larger dams.
ISSN:21905452
21905479
DOI:10.1007/s13349-024-00785-x