입자기반 개별요소모델을 이용한 암석 균열의 수리역학 거동해석: 국제공동연구 DECOVALEX-2023 Task G (Benchmark Simulation)
Hydro-Mechanical Modeling of Fracture Opening and Slip using Grain-Based Distinct Element Model: DECOVALEX-2023 Task G (Benchmark Simulation)
0
조회
0
다운로드
5
인용
0
참고문헌
키워드
초록
본 연구에서는 입자기반 개별요소모델(grain-based distinct element model, GBDEM)을 이용하여 암석 균열의 역학적, 수리적 거동을 평가할 수 있는 수치해석기법을 제시하고 해석해와의 비교를 통해 검증하였다. 이는 DECOVALEX-2023 프로젝트 Task G의 일환으로 수행된 벤치마크 모델링 연구로, Task G는 결정질 암반 내 균열의 열-수리-역학적 복합거동을 해석하기 위한 수치해석기법을 개발하는 데에 목표가 있다. 본 연구에서는 사면체 개별 입자들을 이용하여 해석모델을 생성하고 3DEC을 이용하 여 입자와 접촉에서의 거동을 해석하였다. 이 과정에서 등가연속체 개념을 적용해 입자기반모델의 미시 물성을 산정할 수 있는 새로운 기법을 제시하였다. 한편, 균열 경사각과 거칠기, 경계응력조건 및 압력 조 건에 따른 해석을 실시하여 각 해석조건이 균열의 수직, 전단방향 거동에 미치는 영향을 살펴보았다. 해 석 결과, 제안된 수치모델은 경계응력에 따른 균열의 미끄러짐(fracture slip)과 유체 압력에 따른 균열 의 개방(fracture opening), 균열 경사에 따른 응력 분포, 거칠기로 인한 전단변위의 구속 등을 합리적 으로 재현하고 있음을 확인하였다. 수치해석을 통해 계산된 균열의 수직방향, 전단방향 변위는 모두 해 석해를 통해 계산된 값과 거의 일치하는 결과를 보였다. 본 연구의 해석모델은 Task G에 참여하는 국외 연구팀들과의 의견 교류와 워크숍을 통해 지속적으로 개선하는 한편, 향후 다양한 조건의 실내시험에 적 용하여 타당성을 검증할 예정이다.
Abstract
We proposed a numerical method to simulate the hydro-mechanical behavior of rock fracture using a grain-based distinct element model (GBDEM) in the paper. As a part of DECOVALEX-2023 Task G, we verified the method via benchmarks with analytical solutions. DECOVALEX-2023 Task G aims to develop a numerical method to estimate the coupled thermo-hydro-mechanical processes within the crystalline rock fracture network. We represented the rock sample as a group of tetrahedral grains and calculated the interaction of the grains and their interfaces using 3DEC. The micro-parameters of the grains and interfaces were determined by a new methodology based on an equivalent continuum approach. In benchmark modeling, a single fracture embedded in the rock was examined for the effects of fracture inclination and roughness, the boundary stress condition and the applied pressure. The simulation results showed that the developed numerical model reasonably reproduced the fracture slip induced by boundary stress condition, the fracture opening induced by fluid injection, the stress distribution variation with fracture inclination, and the fracture roughness effect. In addition, the fracture displacements associated with the opening and slip showed good agreement with the analytical solutions. We expect the numerical model to be enhanced by continuing collaboration and interaction with other research teams of DECOVALEX-2023 Task G and validated in further study experiments.
참고문헌 (34)
- Asadi, M. S, "A bonded particle model simulation of shear strength and asperity degradation for rough rock fractures", Rock Mech. Rock Eng, 45(5), pp.649~675 (2012)
- Birkholzer, J.T, "DECOVALEX-2023 Introduction", Presented in DECOVALEX-2023 2nd Workshop (2020)
- Birkholzer, J. T, "25 years of DECOVALEX-Scientific advances and lessons learned from an international research collaboration in coupled subsurface processes", International Journal of Rock Mechanics and Mining Sciences, 122, pp.103995~ (2019)
- Castro-Filgueira, U, "Particle flow code simulation of intact and fissured granitic rock samples", Journal of Rock Mechanics and Geotechnical Engineering, 12(5), pp.960~974 (2020)
- Cho, N, "A clumped particle model for rock", Int. J. Rock Mech. Min. Sci, 44, pp.997~1010
- Cundall, P.A, "Formulation of a three-dimensional distinct element model—Part I. A scheme to detect and represent contacts in a system composed of many polyhedral blocks", International Journal of Rock Mechanics and Mining Sciences &Geomechanics Abstracts, 25(3), pp.107~116 (1988)
- Fu, T. F, "Mesoscopic time-dependent behavior of rocks based on three-dimensional discrete element grain-based model", Computers and Geotechnics, 121, pp.103472~ (2020)
- Geuzaine, C, "Gmsh: A 3‐D finite element mesh generator with built‐in pre‐and post‐processing facilities", International journal for numerical methods in engineering, 79(11), pp.1309~1331 (2009)
- Ghazvinian, E, "3D random Voronoi grain-based models for simulation of brittle rock damage and fabric-guided micro-fracturing", Journal of Rock Mechanics and Geotechnical Engineering, 6(6), pp.506~521 (2014)
- Gu, D, "A complex rock topple-rock slide failure of an anaclinal rock slope in the Wu Gorge", Yangtze River, China. Engineering Geology, 208, pp.165~180 (2016)
- Hu, Z, "Stability Analysis of the Arch Crown of a Large-Scale Underground Powerhouse During Excavation", Rock Mechanics and Rock Engineering, 53(6), pp.1~9 (2020)
- Itasca Consulting Group Inc, "UDEC (Universal Distinct Element Code) version 6.0" (2014), Itasca CGI
- Itasca Consulting Group Inc, "3DEC (3 Dimensional Distinct Element Code) version 5.2" (2017), Itasca CGI
- "PFC (Particl Flow Code) online manual" (2021)[URL]
- Lan, H. X, "Effect of heterogeneity of brittle rock on micromechanical extensile behavior during compression loading", Journal of Geophysical Research: Solid Earth, 115, pp.B1~ (2010)
- Li, A, "Analysis of a complex flexural toppling failure of large underground caverns in layered rock masses", Rock Mechanics and Rock Engineering, 52(9), pp.3157~3181 (2019)
- Li, Z, "Quantitative determination of PFC3D microscopic parameters", Journal of Central South University, 28(3), pp.911~925 (2021)
- Lisjak, A, "Numerical modelling of the anisotropic mechanical behaviour of opalinus clay at the laboratory-scale using FEM", DEM, 2014, pp.47(1), 187~206
- Ma, Q, "Mechanical and energy characteristics of coal–rock composite sample with different height ratios : a numerical study based on particle flow code", Environmental Earth Sciences, 80(8), pp.1~14 (2021)
- Mahabadi, O. K, "A novel approach for micro-scale characterization and modeling of geomaterials incorporating actual material heterogeneity", Geophysical Research Letters, 39(1), pp.1~6 (2012)
- 박정욱, "입자기반 개별요소모델을 통한 결정질 암석 내 균열의 역학적 거동 모델링: 국제공동연구 DECOVALEX-2023 Task G(Benchmark Simulation)", 터널과 지하공간, 30(6), pp.573~590 (2020), 한국암반공학회
- Park, J. W, "Polygonal grain-based distinct element modeling for mechanical behavior of brittle rock", International Journal for Numerical and Analytical Methods in Geomechanics, 41(6), pp.880~898 (2017)
- Park, J.W, "Numerical simulation of a direct shear test on a rock joint using a bonded-particle model", Int. J. Rock Mech. Min. Sci, 46, pp.131~1328 (2009)
- Parker, A.P, "The mechanics of fracture and fatigue: An introduction", pp.174~ (1981), E. & F. N. Spon, Ltd
- Pollard, D.D, "Fracture mechanics of rock", pp.277~347 (1987)
- Potyondy, D.O, "A grain-based model for rock: approaching the true microstructure", Proceedings of Bergmekanikk I Norden (2010)
- Potyondy, D.O, "A flat-jointed bonded-particle material for hard rock", Proceedings of 46th U.S. Rock mechanics, 2012, ~
- Potyondy, D.O, "PFC3D flat joint contact model version1" (2013), Itasca Consulting Group
- David Oskar Potyondy, "The bonded-particle model as a tool for rock mechanics research and application: current trends and future directions", Geosystem Engineering, 18(1), pp.1~28 (2015), 한국자원공학회
- Potyondy, D.O, "A bonded-particle model for rock", Int. J. Rock Mech. Min. Sci, 41(8), pp.1329~1364 (2004)
- Potyondy, D.O, "Effects of stress and induced cracking on the static and dynamic moduli of rock", Proceedings of First International FLAC, 2008, 147~156
- Wang, Z, "Investigation of microcracking behaviors in brittle rock using polygonal grain‐based distinct method", International Journal for Numerical and Analytical Methods in Geomechanics (2021)
- Wu, Z, "Investigation of the characteristics of rock fracture process zone using coupled FEM", DEM method, 2018, pp.200, 355~374
- Yoon, J, "Discrete element modeling of fluid injection–induced seismicity and activation of nearby fault 1", Can. Geotech. J, 52(10), pp.1457~1465 (2015)