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Resistivity monitoring for internal erosion detection at Hallby embankment dam

Sjödahl, Pontus LU ; Dahlin, Torleif LU and Johansson, Sam (2004) Progress in Environmental and Engineering Geophysics: Proceedings of the International Conference on Environmental and Engineering Geophysics, ICEEG 2004 In Progress in Environmental and Engineering Geophysics: Proceedings of the International Conference on Environmental and Engineering Geophysics, ICEEG 2004 p.310-316
Abstract
Internal erosion is one of the major reasons for embankment dam failures. Despite this, the knowledge of the temporal development of internal erosion in full scale structures is limited. Results from a research field monitoring program by daily resistivity measurements in Sweden clearly show long term changes in resistivity in the embankment dam. The results indicate that resistivity monitoring can detect development of internal erosion at an early stage, as resistivity variation is caused by changes in the material as well as changes in the seepage flow. The method can be used where intrusive investigations are normally avoided. Embankment dams are generally constructed with a low permeable core, one or more surrounding filters and... (More)
Internal erosion is one of the major reasons for embankment dam failures. Despite this, the knowledge of the temporal development of internal erosion in full scale structures is limited. Results from a research field monitoring program by daily resistivity measurements in Sweden clearly show long term changes in resistivity in the embankment dam. The results indicate that resistivity monitoring can detect development of internal erosion at an early stage, as resistivity variation is caused by changes in the material as well as changes in the seepage flow. The method can be used where intrusive investigations are normally avoided. Embankment dams are generally constructed with a low permeable core, one or more surrounding filters and support fill. In practise, an electrode layout along the dam crest, or preferably electrodes buried in the top of the core, is the most sensible installation for resistivity monitoring on existing dams. It is important to pass the current through the conductive core, which is the main target of investigation. Moreover, the installation must be done in a way that allows high accuracy measurements. Monitoring equipment as well as data handling and monitoring routines must also be able to handle the small resistivity variations that occur in the dam. If so, methods of analysing and comparing the seasonal resistivity variation schemes in the reservoir and inside the dam body are capable of identifying areas with anomalous seepage, and in some cases also internal erosion. Hallby was the first Swedish embankment to get a permanently installed monitoring system intended for resistivity measurements. Daily measurements started to take place already in late 1996. This paper includes examples of long term time series from Hallby along with some evaluation and interpretation techniques used when analysing such monitoring data. Increasing resistivity and larger variations have been noticed in a particular zone in the left embankment. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
Resistivity, Rockfills, Internal erosion, Seepage flow
in
Progress in Environmental and Engineering Geophysics: Proceedings of the International Conference on Environmental and Engineering Geophysics, ICEEG 2004
pages
310 - 316
publisher
Science Press
conference name
Progress in Environmental and Engineering Geophysics: Proceedings of the International Conference on Environmental and Engineering Geophysics, ICEEG 2004
external identifiers
  • WOS:000223170000054
  • Scopus:17044385447
ISBN
1880132974
language
English
LU publication?
yes
id
87a0a28e-0000-4867-8709-64be9ebcdee7 (old id 615089)
date added to LUP
2007-12-04 09:22:53
date last changed
2016-10-13 04:51:25
@misc{87a0a28e-0000-4867-8709-64be9ebcdee7,
  abstract     = {Internal erosion is one of the major reasons for embankment dam failures. Despite this, the knowledge of the temporal development of internal erosion in full scale structures is limited. Results from a research field monitoring program by daily resistivity measurements in Sweden clearly show long term changes in resistivity in the embankment dam. The results indicate that resistivity monitoring can detect development of internal erosion at an early stage, as resistivity variation is caused by changes in the material as well as changes in the seepage flow. The method can be used where intrusive investigations are normally avoided. Embankment dams are generally constructed with a low permeable core, one or more surrounding filters and support fill. In practise, an electrode layout along the dam crest, or preferably electrodes buried in the top of the core, is the most sensible installation for resistivity monitoring on existing dams. It is important to pass the current through the conductive core, which is the main target of investigation. Moreover, the installation must be done in a way that allows high accuracy measurements. Monitoring equipment as well as data handling and monitoring routines must also be able to handle the small resistivity variations that occur in the dam. If so, methods of analysing and comparing the seasonal resistivity variation schemes in the reservoir and inside the dam body are capable of identifying areas with anomalous seepage, and in some cases also internal erosion. Hallby was the first Swedish embankment to get a permanently installed monitoring system intended for resistivity measurements. Daily measurements started to take place already in late 1996. This paper includes examples of long term time series from Hallby along with some evaluation and interpretation techniques used when analysing such monitoring data. Increasing resistivity and larger variations have been noticed in a particular zone in the left embankment.},
  author       = {Sjödahl, Pontus and Dahlin, Torleif and Johansson, Sam},
  isbn         = {1880132974},
  keyword      = {Resistivity,Rockfills,Internal erosion,Seepage flow},
  language     = {eng},
  pages        = {310--316},
  publisher    = {ARRAY(0x8e49f00)},
  series       = {Progress in Environmental and Engineering Geophysics: Proceedings of the International Conference on Environmental and Engineering Geophysics, ICEEG 2004},
  title        = {Resistivity monitoring for internal erosion detection at Hallby embankment dam},
  year         = {2004},
}