ABSTRACT The diversion length of a capillary barrier is increased with the introduction of a well-sorted sand layer immediately above the fine/coarse interface. Various soils were evaluated as "transport layer" materials using numerical simulation. Infiltration and evapotranspiration were simulated for one year of an Albuquerque, NM, climate. The infiltration and evapotranspiration varied daily in the simulations with the use of a daily effective flux. The baseline simulation without a transport layer diverted moisture 5 m. The diversion length was increased to 37 m with the use of a construction sand layer, and a layer of 100-mesh sand did not allow any moisture to penetrate the barrier. The simulation results are consistent with the field test results of Stormont , which indicate an increase of capillary barrier diversion length with the introduction of a sand transport layer. A capillary barrier may be an inexpensive and stable method of improving performance of cover systems in semi-arid regions.
KEYWORDS: capillary barriers, unsaturated flow, lateral diversion landfill covers
This paper is from the Proceedings of the HSRC/WERC Joint Conference on the Environment, May 1996, published in hard copy and on the Web by the Great Plains/Rocky Mountain Hazardous Substance Research Center.
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