MX80 벤토나이트 펠렛의 열-수리-역학적 복합거동 모델링
Numerical Modeling of Coupled Thermo-hydro-mechanical Behavior of MX80 Bentonite Pellets
0
조회
0
다운로드
2
인용
0
참고문헌
키워드
초록
MX80 벤토나이트 펠렛에서의 열-수리-역학적 복합거동 특성을 파악하고자 TOUGH2-FLAC3D 시뮬레이터를 이용하여 스페인 CIEMAT에서 수행된 컬럼 시험에 대한 수치해석을 수행하였다. 수치해석에서는 실험실에서 사용된 것과 동일한 히터 파워와 물 주입압을 경계조건으로 설정하고 해석을 수행하였다. 사용된 열-수리 모델이 벤토나이트 펠렛의 복합거동 예측에 적용하기 적합한지 판단하기 위해 가열과 물 주입에 의한 벤토나이트 펠렛에서의 온도와 상대습도 변화를 시간 경과에 따라 잘 예측할 수 있는지를 살펴보았다. 계산된 결과가 계측된 온도와 상대습도 변화 경향을 적절하게 재현 할 수 있었기 때문에 사용된 열-수리 모델은 벤토나이트 펠렛의 열-수리 복합거동을 예측하고 재현하기에 적절한 것으로판단된다. 하지만, 물 주입 이후의 계산된 응력변화가 상대적으로 작고 느리게 변화되는 것으로 보아 사용된 탄성모델과 스웰링 모델에 한계점이 존재하는 것으로 보이며, 사용된 두 역학 모델로 완충재의 복잡한 열-수리-역학적 복합거동을 현실적으로 재현하기에 부족한 것으로 판단된다.
Abstract
Numerical simulations of CIEMAT column test in Spain are performed to investigate the coupled thermo-hydro-mechanical (THM) behavior of MX80 bentonite pellets using TOUGH2-FLAC3D. The heater power and injection pressure of water in the numerical simulations are identical to those in the laboratory test. To investigate the applicability of the thermo-hydraulic (TH) model used in TOUGH2 code to prediction of the coupled TH behavior, the simulation results are compared with the observations of temperature and relative humidity with time. The tendencies of the coupled behavior observed in the test are well represented by the numerical models and the simulator in terms of temperature and relative humidity evolutions. Moreover, the performance of the models for the reproduction and prediction of the coupled TH behavior is globally satisfactory compared with the observations. However, the calculated stress change is relatively small and slow due to the limitations of the simple elastic and swelling pressure model used in numerical simulations. It seems that the two models are insufficient to realistically reproduce the complex coupled THM behavior in the bentonite pellets.
참고문헌 (20)
- Alonso E. E., "A constitutive model for partially saturated soils", Geotechnique, 40(3), pp.405~430 (1990)
- Birkholzer, J. T., "25 years of DECOVALEX - Scientific advances and lessons learned from an international research collaboration in coupled subsurface process", International Journal of Rock Mechanics and Mining Sciences, 122, pp.103995~ (2019)
- "CODE BRIGHT, A 3D program for thermo-hydro-mechanical analysis in geological media manual" (2004), UPC
- FEBEX project. Full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock, "ENRESA", ENRESA, ~ (2000)
- The HE-E Experiment: Lay-out, Interpretation and THM Modelling, "Gaus, I", NAB, ~, pp.Nagra Arbeitsbericht NAB 14-53 (2014)
- Gens, A., "Modern Issues in Non-saturated Soils", pp.129~158 (1995), Springer-Verlag
- FLAC3D, Fast Lagrangian Analysis of Continua in 3 Dimensions, Version 4.0, "Itasca", Itasca Consulting Group, ~ (2009)
- Jacinto, A. C., "Adaptation of the van Genuchten expression to the effects of temperature and density for compacted bentonites", Applied Clay Science, 42, pp.575~582 (2009)
- Kwon, S., "Thermo-mechanical coupling analysis of APSE using submodels and neural networks", Journal of Rock Mechanics and Geotechnical Engineering, 5, pp.32~43 (2013)
- 이창수, "TOUGH2-MP", FLAC3D의 Barcelona Basic Model 해석 모듈 개발, 2020, pp.30(1), 39~62[DOI]
- 이창수, "불포화토의 열･탄소성 거동 분석을 위한 Barcelona Basic Model 소개", 터널과 지하공간, 29(1), pp.38~51 (2019), 한국암반공학회[DOI]
- 이창수, "2008년부터 2019년까지 수행된 국제공동연구 DECOVALEX 소개", 터널과 지하공간, 30(4), pp.271~305 (2020), 한국암반공학회
- Pre-dismantling THM modelling of the FEBEX in situ experiment, "Papafotiou, A", NAB, ~, pp.Nagra Arbeitsbericht NAB 16-22 (2017)
- TOUGH2 User’s Guide, Version 2.0, "Pruess, K.", Lawrence Berkeley National Laboratory, ~, pp.Report LBNL-43134 (1999)
- Rutqvist, J., "Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations", Comput Geosci, 37(6), pp.739~750 (2011)
- Rutqvist, J., "Implementation of the Barcelona Basic Model into TOUGH-FLAC for simulations of the geomechanical behavior of unsaturated soils", Computer & Geosciences, 37, pp.751~762 (2011)
- Rutqvist, J., "A modeling approach for analysis of coupled multiphase fluid flow, heat transfer, and deformation in fractured porous rock", Int J Rock Mech Min Sci, 39(4), pp.429~442 (2002)
- Salas, J., "Hydrogeochemical evolution of the bentonite buffer in a KBS-3 repository for radioactive waste. Reactive transportmodelling of the LOT A2 experiment", Applied Clay Science, 101, pp.521~532 (2014)
- Long-term THM tests reports: THM cells for the HE-E test: Update of results until February 2014, "Villar, M. V.", CIEMAT, ~, pp.PEBS Report D2.2-7.3 (2014)
- THM cells for the HE-E test: setup and first results, "Villar, M. V.", CIEMAT, ~, pp.PEBS Report D2.2.7a (2012)