Experimental Study on Frictional Healing Behavior of Rock Joints in the Natural Barriers under Hydro-Mechanical Conditions

Yong-Ki Lee; Seungbeom Choi; Kyung-Woo Park; Jin-Seop Kim; Taehyun Kim

doi:10.7474/TUS.2023.33.1.042

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2023 Vol.33, Issue 1 Preview Page Next Page

Original Article

Experimental Study on Frictional Healing Behavior of Rock Joints in the Natural Barriers under Hydro-Mechanical Conditions 천연방벽 내 암반 절리의 수리-역학적 조건에서의 마찰회복 거동에 대한 실험적 연구

28 February 2023. pp. 42-56

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Abstract

In deep geological disposal of high-level radioactive waste (HLW), the natural barrier must physically support the disposal facility and delay the movement of radionuclides for at least hundreds of thousands of years. To evaluate the long-term geological evolution of the natural barriers, it is essential to analyze the long-term behavior of rock joints, including the frictional healing behavior. This study aimed to experimentally analyze the frictional healing behavior of rock joints under hydro-mechanical (H-M) conditions through the slide-hold-slide (SHS) test. The SHS tests were performed under mechanical and H-M conditions for joint specimens of different roughness. In the H-M conditions, the frictional healing rate tended to increase, which was more evident in the specimens with large roughness. In addition, it was confirmed that the effect of the hydro-mechanical conditions was more significant when the effective normal stress acting on the joint surface was small. These results are expected to be used as fundamental data to understand the frictional healing behavior of rock joints in the natural barriers.

Keywords

Natural barriers

Rock joints

Frictional healing

Hydro-mechanical conditions

Slide-hold-slide test

고준위방사성폐기물의 심층처분시스템에서 천연방벽은 처분시설을 물리적으로 지지함과 동시에 방사성 핵종의 이동을 지연시키는 역할을 최소 수십만년 이상 수행해야 한다. 천연방벽의 지구조적 장기진화 평가를 위해서는 암반 절리의 장기거동 분석이 필수적이며, 여기에는 마찰회복 거동이 포함된다. 본 연구에서는 암반 절리의 수리-역학적 조건 하 마찰회복 거동을 슬라이드-홀드-슬라이드(slide-hold-slide, SHS) 실험을 통해 실험적으로 분석해 보고자 하였으며, 이를 위해 서로 다른 거칠기의 절리 시험편을 대상으로 역학적 및 수리-역학적 조건에서 SHS 실험을 수행하였다. 수리-역학적 조건에서 마찰회복률은 더 증가하는 경향을 보였으며, 이는 거칠기가 큰 시험편에서 더 분명하게 나타났다. 또한, 절리면에 작용하는 유효 수직응력이 작은 경우에 수리-역학적 조건의 영향이 더 크게 작용함을 확인할 수 있었다. 이러한 결과들은 천연방벽 암반 절리의 마찰회복 거동을 파악하는 데 유용한 기초자료로 활용될 수 있을 것으로 기대된다.

키워드

천연방벽

암반 절리

마찰회복

수리-역학적 조건

슬라이드-홀드-슬라이드 실험

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Information

Publisher :Korean Society for Rock Mechanics and Rock Engineering
Publisher(Ko) :한국암반공학회
Journal Title :Tunnel and Underground Space
Journal Title(Ko) :터널과 지하공간
Volume : 33
No :1
Pages :42-56
Received Date : 2023-02-14
Revised Date : 2023-02-21
Accepted Date : 2023-02-21
DOI :https://doi.org/10.7474/TUS.2023.33.1.042

Tunnel and Underground SpaceISSN:1225-1275(Print) 2287-1748(Online)한국암반공학회

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