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2025 Vol.35, Issue 2 Preview Page

Research Article

Thixotropic Behavior of Artificial Fault Core Specimens with Buncheong Clay

분청토를 이용한 인공 단층핵 시료의 틱소트로피 거동

Yu-Jin Ha1
,
Se-Jeong Ju2
,
Hyeong-Sin Kim3
,
MinJi Kang4
,
Yong-Seok Seo5*
하 유진1
,
주 세정2
,
김 형신3
,
강 민지4
,
서 용석5*
1Ph.D. Student, Department of Earth and Environmental Sciences, Chungbuk National University
2Master’s Student, Department of Earth and Environmental Sciences, Chungbuk National University
3Lecturer, Department of Earth and Environmental Sciences, Chungbuk National University
4Senior Staff, Division of Geotechnical Design, Younsung ENG
5Professor, Department of Earth and Environmental Sciences, Chungbuk National University
1충북대학교 지구환경과학과 박사과정
2충북대학교 지구환경과학과 석사과정
3충북대학교 지구환경과학과 강사
4(주)윤성이엔지 지반설계부 주임
5충북대학교 지구환경과학과 교수
*Corresponding Author
30 June 2025. pp. 225-230
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Abstract

Laboratory tests were conducted to investigate the permeability and shear characteristics of artificial fault core samples. Due to the difficulty of preparing natural fault core samples, buncheong clay was used in place of fault gouge to fabricate the test specimens. To assess the development of thixotropy (i.e., the time-dependent physical characteristics of clay specimens), permeability and direct shear tests were carried out at 3, 7, 14, 21, and 28 days after specimen preparation. The results of variable-head permeability tests indicate a substantial decrease in hydraulic conductivity, from 2.98 × 10-3 to 5.97 × 10-6 cm/sec on day 3 to 1.27 × 10-6 to 5.09 × 10-7 cm/sec on day 28. In addition, the range of hydraulic conductivity values decreased over time, indicating reduced variability. Direct shear tests showed a gradual increase in the internal friction angle from 23° to 38° over the same period. These hydraulic and mechanical changes are attributed to the development of thixotropy, and it is inferred that the clay particles undergo microstructural rearrangement over time, leading to a more stable structure.

Keywords
artificial fault core specimen
buncheong clay
thixotropy
hydraulic conductivity
friction angle

본 연구에서는 인공 단층핵 시료의 투수특성과 전단특성을 파악하기 위하여 실내시험을 실시하였다. 자연 단층핵 시료의 제작상 어려움 때문에 단층점토 대신 분청토를 이용하여 시료를 제작하였다. 점토시료의 물리적 특성인 시간경과에 따른 틱소트로피 현상의 발현을 확인하기 위하여 시료 제작 후 3일, 7일, 14일, 21일, 28일 경과한 후에 실내 투수시험과 직접전단시험을 실시하였다. 실내 투수시험 시 수리전도도는 3일차에 2.98 × 10-3 ~ 5.97 × 10-6 cm/sec, 28일차에 1.27 × 10-6 ~ 5.09 × 10-7 cm/sec로 감소하였으며, 시간이 경과함에 따라 수리전도도의 분산 정도가 감소하는 경향을 보였다. 직접전단시험 시 내부마찰각은 3일차에 23°에서 28일 경과 후 38°로 증가하였다. 이러한 수리 ‧ 역학적 변화는 틱소트로피 발현에 기인하며, 시간이 경과함에 따라 점토입자가 재배열되면서 안정된 것으로 판단된다.

키워드
인공 단층핵 시료
분청토
틱소트로피
수리전도도
마찰각
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Information
  • Publisher :Korean Society of Engineering Geology
  • Publisher(Ko) :대한지질공학회
  • Journal Title :The Journal of Engineering Geology
  • Journal Title(Ko) :지질공학
  • Volume : 35
  • No :2
  • Pages :225-230
  • Received Date : 2025-05-26
  • Revised Date : 2025-06-18
  • Accepted Date : 2025-06-25
  • DOI :https://doi.org/10.9720/kseg.2025.2.225
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