A Basic Study on Micro-Electric Potential accompanied with Specimen Failure during Uniaxial Compressive Test

일축 압축에 의한 시료 파괴 시 수반되는 미소 전위에 대한 기초 연구

  • 김종욱 (한국지질자원연구원 지반안전연구부 지반탐사연구실) ;
  • 박삼규 (한국지질자원연구원 지반안전연구부 지반탐사연구실) ;
  • 송영수 (전북대학교 자원.에너지공학과) ;
  • 성낙훈 (한국지질자원연구원 지반안전연구부 지반탐사연구실) ;
  • 김정호 (한국지질자원연구원 지반안전연구부 지반탐사연구실) ;
  • 조성준 (한국지질자원연구원 지반안전연구부 지반탐사연구실)
  • Published : 2007.08.31

Abstract

As a part of basic studies on monitoring of landslides and slope stability using SP measurements, micro-electric potentials of rock samples were measured accompanied with the rock failure by a uniaxial loading test were measured. The measurement system consists of a 8 channel A/D converter with 24 bit resolution, uniaxial loading tester, strain gages and 4 sets of electrode attached to a rock sample. Rock samples of granite, limestone, and sandstone were tested. Also, mortar samples were tested in order to monitor electric-potentials of a uniform sample. Micro-electric potentials were detected in all saturated samples and the strength of them increased as the loading force increased. Sandstone samples showed the largest strength of micro-electric potential and it followed limestone and granite samples, which indicates a positive relationship with porosity of rocks. The mechanism generating these micro-electric potential can be explained in terms of electro-kinetics. In case of dry samples, micro-electric potential could be observed only in sandstone samples, where piezoelectric effect played main role due to high contents of quartz in sandstone samples. We found that biggest micro-electric potentials were observed at the electrodes near the crack surface of rock samples. This is very encouraging result that SP monitoring can be applied to predicting landsliding or to estimate collapsing position combining with monitoring of acoustic emissions.

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