A Numerical Study on Rock Mechanics for a Deep Geological Disposal Facility Considering the Deep Subsurface Environment in Korea

Min-Jun Kim; Dae-Sung Cheon; Jai-Yong Park; Min-Seok Kim; Hyung-Ju Yun

doi:10.7474/TUS.2025.35.5.513

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2025 Vol.35, Issue 5 Preview Page Next Page

Original Article

A Numerical Study on Rock Mechanics for a Deep Geological Disposal Facility Considering the Deep Subsurface Environment in Korea 국내 심부환경과 처분개념을 고려한 심층처분시설의 암반역학적 수치해석 연구

31 October 2025. pp. 513-534

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Abstract

This study aims to evaluate the rock mechanical feasibility of deep geological disposal facilities by constructing a numerical model that reflects the rock properties of representative domestic crystalline rock formations. Representative cases were established for both vertical and horizontal disposal concepts. Rock properties, lateral stress ratios, and initial in-situ stresses reflecting the domestic deep geological conditions were applied as input parameters for the simulation. Stress redistribution and strain distribution around disposal tunnels and deposition holes during excavation were analyzed, and key stability indicators such as localized zones of maximum principal stress, strain concentration, and plastic deformation regions were identified. In the reference case, under the initial condition without engineered barriers, the maximum principal stress acting on the surrounding rock remained lower than the rock strength, indicating an overall stable stress condition. In contrast, under conditions with lower rock strength and a higher lateral stress coefficient, localized plastic deformation was observed around the disposal tunnels and boreholes. These results demonstrate that the rock mechanical stability of the disposal system is sensitive to rock properties and initial stress states. The findings of this study can serve as a quantitative basis for assessing rock mechanical stability in the conceptual design stage of disposal facilities and contribute to evaluating the safety margin of the natural barrier.

Keywords

Deep subsurface environment in Korea

Deep geological repository

Rock mechanics

Numerical analysis

본 연구에서는 심층처분시설의 암반역학적 타당성 평가를 목적으로, 국내 대표 후보 암종의 물성을 기반으로 수치해석 모델을 구성하고, 수직처분 및 수평처분 방식에 대해 각각 대표 해석 사례를 설정하였다. 해석 조건으로는 국내 심부환경을 반영한 지반 정수, 측압계수, 현지응력 초기조건을 적용하였다. 굴착에 따른 처분터널과 처분공 주변 암반의 응력 재분포 및 변형률 분포를 평가하였으며, 최대 주응력의 국부 집중 영역, 변형률 및 소성영역 등 주요 안정성 지표를 도출하였다. 대표 사례 해석 결과, 공학적 방벽이 적용되지 않은 초기 조건에서 암반에 작용하는 최대 응력이 강도에 비해 낮게 나타나, 전반적으로 안정적인 응력 상태가 유지됨을 확인할 수 있었다. 반면, 지반 정수가 낮고 측압계수가 높은 해석 조건에서는 처분터널과 처분공 주변의 국부 영역에서 소성변형이 발생하였다. 이는 암반의 역학적 안정성이 물성 조건과 초기응력 상태에 민감하게 반응함을 보여준다. 본 연구의 결과는 심층처분시설 개념설계 단계에서 암반역학적 안정성 평가를 위한 정량적 기준과 비교 자료로 활용될 수 있으며, 천연방벽 안전여유의 기술적 검토에 기여할 수 있다.

키워드

국내 심부환경

심층처분시설

암반역학

수치해석

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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 : 35
No :5
Pages :513-534
Received Date : 2025-08-05
Revised Date : 2025-10-10
Accepted Date : 2025-10-13
DOI :https://doi.org/10.7474/TUS.2025.35.5.513

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

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