Changes in the Gas Permeability of Compacted Clay Liner (CCL) Sample under Various Compaction Conditions

摘要

Gas and liquid permeability tests were performed on compacted clay liners (CCL) samples prepared with three different compaction conditions to assess the effectiveness of CCL as a gas barrier. Liquid permeability tests used distilled water as a permeant in the rigid wall permeameter. Gas permeability tests were performed on oven-dried samples using nitrogen. The gas and liquid permeabilities through CCL changed as a function of porosity. As porosity increased from 0.3 to 0.4. gas permeability, k_g, increased from 2.03 X 10~(-10) to 4.96 X 10~(-9) cm~2, and liquid permeability, k_1, increased from 9.28 X 10~(-13) to 7.04 X 10~(-12) cm~2, respectively. The empirical relationship between gas and liquid permeabilities from our data can be expressed as log_(10) k_g = 1.62 X log_(10) k_l + 9.92. The ratio of k_g / k_l ranged from 167 to 1411, indicating that gas permeability is greater than liquid permeability.