Unsaturated properties for non-Darcian water flow in clay

JOURNAL OF HYDROLOGY

卷:430

Article

Liu, Hui-Hai¹  Li, Lianchong¹  Birkholzer, Jens¹ 

[1] Univ Calif Berkeley, Lawrence Berkeley Natl Lab, Div Earth Sci, Berkeley, CA 94720 USA

关键词: Unsaturated flow;    Clay rock;    Non-Darcian flow;    Geological repository;    Shale gas;   

DOI  :  10.1016/j.jhydrol.2012.02.017

来源: Elsevier

【 摘 要 】

Clay rock formations, and compacted clay (e.g., bentonite) used as backfill within disposal drifts, have been considered as natural and engineered barriers, respectively, for isolating high-level nuclear wastes in mined geologic repositories. Accurately modeling unsaturated flow in those clay materials is important for assessing the performance of a geological repository. While the non-Darcian behavior of water flow in clay materials has been demonstrated in the literature, a systematic study of modeling unsaturated non-Darcian flow is still lacking. Based on a hypothesis that pore water in clay becomes non-Newtonian as a result of water-clay interaction, we propose new constitutive relationships for unsaturated flow, including a relationship between water flux and hydraulic gradient and those among capillary pressure, water saturation, and hydraulic conductivity. An evaluation based on a set of laboratory experimental observations supports the usefulness of the proposed relationships. More experimental studies are desirable for further confirming the non-Newtonian water flow behavior in clay materials and evaluating the proposed relationships. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free