The effects of heterogeneities on the performance of capillary barriers for waste isolation
The effects of heterogeneities on the performance of capillary barriers is investigated by simulating three systems comprised of a fine soil layer overlying a coarse gravel layer with homogeneous, layered heterogeneous, and random heterogeneous property fields. The amount of lateral diversion above the coarse layer under steady-state infiltration conditions is compared between the simulations. Results indicate that the performance of capillary barriers may be significantly influenced by the spatial variability of the properties. The layered heterogeneous system performed best as a result of horizontal features within the fine layer that acted as additional local capillary barriers that delayed breakthrough into the coarse layer. The random heterogeneous system performed worst because of channeled flow that produced localized regions of water breakthrough into the coarse layer. These results indicate that engineered capillary barriers may be improved through emplacement and packing methods that induce a layered system similar to the layered heterogeneous field simulated in this study.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE Office of Environmental Restoration and Waste Management, Washington, DC (United States)
- DOE Contract Number:
- AC04-94AL85000
- OSTI ID:
- 432895
- Report Number(s):
- SAND--97-0099C; CONF-970208--2; ON: DE97002471
- Country of Publication:
- United States
- Language:
- English
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