Slime thickness evaluation of bored piles by electrical resistivity probe

Ok Hyun Chun, Hyung Koo Yoon, Min Chul Park, Jong Sub Lee

Research output: Contribution to journalArticlepeer-review

7 Citations (Scopus)


The bottoms of bored piles are generally stacked with soil particles, both while boreholes are being drilled, and afterward. The stacked soils are called slime, and when loads are applied on the pile, increase the pile settlement. Thus to guarantee the end bearing capacity of bored piles, the slime thickness should be precisely detected. The objective of this study is to suggest a new method for evaluating the slime thickness, using temperature compensated electrical resistivity. Laboratory studies are performed in advance, to estimate and compare the resolution of the electrical resistivity probe (ERP) and time domain reflectometry (TDR). The electrical properties of the ERP and TDR are measured using coaxial type electrodes and parallel type two-wire electrodes, respectively. Penetration tests, conducted in the fully saturated sand-clay mixtures, demonstrate that the ERP produces a better resolution of layer detection than TDR. Thus, field application tests using the ERP with a diameter of 35.7. mm are conducted for the investigation of slime thickness in large diameter bored piles. Field tests show that the slime layers are clearly identified by the ERP: the electrical resistivity dramatically increases at the interface between the slurry and slime layer. The electrical resistivity in the slurry layer inversely correlates with the amount of circulated water. This study suggests that the new electrical resistivity method may be a useful method for the investigation of the slime thickness in bored piles.

Original languageEnglish
Pages (from-to)167-175
Number of pages9
JournalJournal of Applied Geophysics
Publication statusPublished - 2014 Sept


  • Bored pile
  • Electrical resistivity probe
  • Field test
  • Layer detection
  • Slime
  • TDR

ASJC Scopus subject areas

  • Geophysics


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