Research on the Sealing Ability of Saturated Compacted Bentonite/Sand Mixture
This paper focuses on the experimental research of water and gas transport in a compacted bentonite/sand mixture under flexible condition. The main contribution of our study is to provide insights into water and gas transport properties in the compacted bentonite/sand mixture. Experimental results indicate that water tightness can be achieved after full saturation, and the water permeability of the sample is at the magnitude of 10−20 m2. Gas breakthrough tests show that gas migration properties depend on both external stress state and internal fluid pressure. In addition, change of the external stress also has a hysteresis effect on the gas transport properties. At certain stage, the increasing rate of downstream gas pressure continue decreasing even though the gas pressure was increased while the confining pressure was kept constant. During the whole process, gas migration properties were determined by the coupling effects of confining pressure and gas pressure.
KeywordsBentonite/sand mixture Water tightness Gas migration Coupling effects
The authors are grateful for the support provided by the Natural Science Foundation of Jiangsu Province of China (BK20160249), the Open Fund (KLE-TJGE-B1703) of Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education (Tongji University) and the Fundamental Research Funds for the Central Universities (China University of Mining and Technology) (2017QNA29).
- King F, Ahonen L, Taxén C, Vuorinen U, Werme L (2001) Copper corrosion under expected conditions in a deep geologic repository, vol 1. Svensk Kärnbränslehantering AB, StockholmGoogle Scholar
- Liu JF, Skoczylas F, Talandier J (2015) Gas permeability of a compacted bentonite-sand mixture: coupled effects of water content, dry density and confining pressure. Can Geotech J 52(99):1–9Google Scholar