On the permeability of compacted and stabilized loessical silts in relation to liner system regulations

NIEVA, PABLO; FRANCISCA, FRANCO MATÍAS

Cochabamba

Congreso; International Congress on Development, Environment and Natural Resources: Multi-level and Multi-scale Sustainability; 2007

Universidad Mayor de San Simón

Hydraulic conductivity (k) is the most important property of compacted soils to determine their aptitude as construction material for liners. Most of liner system regulations specify hydraulic conductivities lower than 1x10-7 cm/s for containment barriers in landfills. In this work, the hydraulic conductivity of loessical silts was measured in two rigid-wall permeameters: compaction-mold and oedometric-cell. Samples were tested at different relative dry unit weights, and various montmorillonite contents. The effect of soil structure on permeability is analyzed. Results show that only 15.9% of compacted silts can attain hydraulic conductivities lower than that required by landfill guidelines. Otherwise, loessical soils must be stabilized with clay to lower their hydraulic conductivities up to acceptable values.