A fully coupled three-dimensional THM analysis of the FEBEX in situ test with the ROCMAS Code: Prediction of THM behavior in a bentonite barrier
- LBNL Library
This paper presents a fully coupled thermal-hydrological-mechanical analysis of FEBEX--a large underground heater test conducted in a bentonite and fractured rock system. System responses predicted by the numerical analysis--including temperature, moisture content, and bentonite-swelling stress--were compared to field measurements at sensors located in the bentonite. An overall good agreement between predicted and measured system responses shows that coupled thermal-hydrological-mechanical processes in a bentonite barrier are well represented by the numerical model. The most challenging aspect of this particular analysis was modeling of the bentonite's mechanical behavior, which at FEBEX turned out to be affected by gaps between prefabricated bentonite blocks. At FEBEX, the swelling pressure did not develop until a few months into the experiment when moisture swelling of bentonite blocks had closed the gaps completely. Moreover, the wetting of the bentonite took place uniformly from the rock and was not impacted by the permeability difference between the Lamprophyres dykes and surrounding rock.
- Research Organization:
- Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
- Sponsoring Organization:
- Swedish Nuclear Power Inspectorate (SKI) Grant No.50062 (US)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 816077
- Report Number(s):
- LBNL--53682
- Country of Publication:
- United States
- Language:
- English
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