A critical reappraisal of residual soils as compacted soil liners

Compacted residual soils are often used as liner materials in engineered landfills, tailings dams, solar ponds, and canals, etc. to minimize the migration of contaminants into the surrounding environment and groundwater. To date, there has not been an extensive and adequate review of the suitability of different residual soil types for use as compacted liner materials. This paper reviews the suitability, merits, demerits, and possible applications of using expansive and lateritic residual soils as compacted soil liners. The review is then complemented by a study of the geotechnical properties of lateritic residual and shrinkable soils from Peninsular Malaysia. Suitability was assessed based on engineering property data for both soil types, collected from various journal papers, workshops, proceedings of conferences, and symposia from around the world. These properties were then compared with the standard requirements for use as liner materials. Descriptive statistics were employed to better assess the individual criteria of using both residual soil types as compacted soil liners. The results indicate that expansive and lateritic soils can be effectively utilized as liner materials if more acceptable materials are not readily available. The study addresses untreated soils but does not discuss the stabilization aspects.